The Roman Catholic view of salvation is one of "salvation by grace" thru merit, that by the grace of God one who believes in the Divine Son of God who died for our sins and rose from the death is forgiven (including so-called Original Sin” even without personal faith), and becomes good enough (via the act itself of water baptism and later Purgatory – for most) to actually be with God. However, since this attainment is said to be enabled by grace, then in Catholicism it is denied that salvation is that of earning salvation. (CCC 2025)

The result of this is that the Catholic gospel of salvation is contrary to Biblical salvation by grace, in which man is in need of salvation for sins he/she has committed, and cannot be saved based upon actual moral worthiness, but is redeemed through effectual regenerating (being not just physically born but born of the Spirit: John 3:5-7) justifying faith - not of works – (Titus 3:5) in the risen Lord Jesus, who saves sinners by His sinless shed blood, and which by faith the believer is accounted righteousness (Romans 4:5; 10:10) on Christ’s account, being “accepted in the Beloved.” (Ephesians 1:6)

For it is this faith that purifies the heart in the washing of regeneration when one effectually believes the gospel, (Acts 10:43; 15:7-9; Titus 3:5) and results in the fruit of obedience/holiness. (Romans 6:22)

Which  fruit evidences that such are believers, and which effectual faith as expressed in obedience by the Holy Spirit (Romans 8:14; Heb. 6:9, 10)

God rewards the justified for, (1 Co. 3:8ff: but not that the believer attained his salvific justified acceptance with God due to his own holiness.

• Therefore the redeemed are those who have been spiritually born of the Spirit (Jn. 3:2-7) by effectual, penitent, heart-purifying, regenerating faith in the Divine Son of God sent be the Father to be the Savior of the world, (1 Jn. 4:14) who saves sinners by His sinless shed blood, on His account.

• And which faith is imputed for righteousness, (Romans 4:5) and which is shown in baptism and following the Lord, (Acts 2:38-47; Jn. 10:27, 28) whom they shall go to be with or His return (Phil 1:23; 2Cor. 5:8 [“we”]; Heb. 12:22, 23; 1Cor. 15:51ff'; 1Thess. 4:17)

• In contrast to those who were never born of the Spirit or who terminally fall away. (Gal. 5:1-4; Heb. 3:12; Heb. 10:25-39) Glory and thanks be to God.

Contrary to Biblical salvation is the RC process of salvation, which begins at baptism which act itself (ex opere operato) is imagined as actually making one righteous enough so that the baptized could go to Heaven if he died right then, before the sin nature that remains makes it manifest that he is not fit to enter Heaven, and which thus (usually) necessitates Purgatory, so that he may once again become good enough to be with God. To wit (emphasis throughout is mine): 

Baptism, the gateway to the sacraments and necessary for salvation by actual reception or at least by desire, is validly conferred only by a washing of true water with the proper form of words. Through baptism men and women are freed from sin, are reborn as children of God, and, configured to Christ by an indelible character, are incorporated into the Church. (Can. 849)

Baptism is a bath that purifies, justifies, and sanctifies. (CCC 1227) The Most Holy Trinity gives the baptized sanctifying grace, the grace of justification... (CCC 1266) Justification is conferred in Baptism, the sacrament of faith. It conforms us to the righteousness of God, who makes us inwardly just by the power of his mercy. (CCC 1992) The grace of Christ is the gratuitous gift...infused by the Holy Spirit into our soul to heal it of sin and to sanctify it. It is the sanctifying or deifying grace received in Baptism. (CCC 1999) 

The Catholic idea maintains that the formal cause of justification does not consist in an exterior imputation of the justice of Christ, but in a real, interior sanctification effected by grace, which abounds in the soul and makes it permanently holy before God (cf. Trent, Sess. VI, cap. vii; can. xi).  

Although the sinner is justified by the justice of Christ, inasmuch as the Redeemer has merited for him the grace of justification (causa meritoria), nevertheless he is formally justified and made holy by his own personal justice and holiness (causa formalis).” (Catholic Encyclopedia>Sanctifying Grace; https://www.newadvent.org/cathen/06701a.htm) 

Thus it is believed that the newly baptized, who are thus inwardly just, formally justified and made holy by their own personal justice and holiness, would go to Heaven if they died before they sin: 

By virtue of our apostolic authority, we define the following: According to the general disposition of God, the souls of all the saints . . . and other faithful who died after receiving Christ's holy Baptism (provided they were not in need of purification when they died, . . .) have been, are and will be in heaven, in the heavenly Kingdom and celestial paradise with Christ, joined to the company of the holy angels. (CCC 1023) 

And  since it is  imagined that  the act itself of baptism renders one good enough to be justified, then  personal, repentant faith is not necessary on the part of the baptized, (Can. 867-871) but that at the least, only that the baptizer has the right matter, right form (including the proper form of words: Can. 849), plus right intention.  ( 861 §2) 

 Therefore, while:

 the sacraments which produce their effects ex opere operato [by the act itself], hence attention is not necessary for the valid reception of the sacraments. One who might be distracted, even voluntarily, during the conferring, e.g. of Baptism, would receive the sacrament validly;” (The Catholic Encyclopedia>Sacraments)

yet the requirements of  right matter, right form (including the proper form of words: Can. 849), plus right intention renders the validity of many baptisms, and thus salvation, to be   doubtful or invalid, according to the church that Catholics are to trust in. (https://www.americamagazine.org/faith/2022/02/17/invalid-baptism-arizona-242422)

Thus "Thousands of baptisms presumed invalid due to one priest’s wording error." (https://www.americamagazine.org/faith/2022/02/17/invalid-baptism-arizona-242422)

Especially in the case of baptized Protestants:

Even in cases where a ceremony had certainly been performed, reasonable doubt of validity will generally remain, on account of either the intention of the administrator or the mode of administration (The Catholic Encyclopedia>Baptism (regarding baptism by “heretics”):

Thus who knows how many baptisms   are Catholic-invalid, of no  effect, since not only can one word ("we" versus "I") invalidate a baptism, but  "The Church teaches very unequivocally that for the valid conferring of the sacraments, the minister must have the intention of doing at least what the Church does." (Catholic Encyclopedia>intention)

However, presuming the sacrament has its intended (imagined)  effect,  yet  since the unholy sinful Adamic nature is all too alive and manifests itself in these "inwardly just" (righteous souls), then the newly baptized all too soon realized he is no longer good enough to be with God.

certain temporal consequences of sin remain in the baptized , such as suffering, illness, death, and such frailties inherent in life as weaknesses of character, and so on, as well as an inclination to sin that Tradition calls concupiscence. .. (CCC 1264) 

Which means that unless they died having  attained to the level of practical perfection needed, then they are in in need of postmortem  purification commencing at death, even  "through fire and torments or "purifying" punishments.  (Apostolic Constitution on Indulgences, Pope Paul VI) For

And thus, what flows from the original error of believing man must actually become good enough to be with God (rather than faith being counted/imputed for righteous, - Rm. 4:5 - and with obedience and holiness being evidential fruit of regenerating faith) is that of the doctrine of RC Purgatory, by which, besides atoning for sins not sufficiently expiated on earth, serves to make the baptized good enough to be with God. 

The Catholic Encyclopedia also states that St. Augustine "describes two conditions of men; "some there are who have departed this life, not so bad as to be deemed unworthy of mercy, nor so good as to be entitled to immediate happiness " etc. (City of God XXI.24.)  

And thus by the close of the fourth century was taught "a place of purgation..from which when purified they "were admitted unto the Holy Mount of the Lord". For " they were "not so good as to be entitled to eternal happiness ". 

One "cannot approach God till the purging fire shall have cleansed the stains with which his soul was infested." (Catholic Encyclopedia>Purgatory) 

All who die in God's grace and friendship, but still imperfectly purified, are indeed assured of their eternal salvation; but after death they undergo purification, so as to achieve the holiness necessary to enter the joy of heaven. (CCC 1030) 

"The purpose of purgatory is to bring you up the level of spiritual excellence needed to experience the full-force presence of God." (Jimmy Akin, How to Explain Purgatory to Protestants). 

"Every trace of attachment to evil must be eliminated, every imperfection of the soul corrected." Purification must be complete..." "This is exactly what takes place in Purgatory." — John Paul II, Audiences, 1999; http://w2.vatican.va/content/john-paul-ii/en/audiences/1999/documents/hf_jp-ii_aud_04081999.html 

Catholic professor Peter Kreeft states, 

"...we will go to Purgatory first, and then to Heaven after we are purged of all selfishness and bad habits and character faults." Peter Kreeft, Because God Is Real: Sixteen Questions, One Answer, p. 224

However, this premise of perfection of character for final salvation eliminates the newly baptized from entering Heaven (if they died before they sinned), since while innocent (not that the act of baptism actually regenerates, as  Catholicism teaches), yet they have not yet attained to "spiritual excellence," to  elmination of "every trace of attachment to evil," to "perfection of the soul," to the level of practical holiness necessary to enter the joy of heaven. 

And this premise would also exclude the contrite criminal of Luke 23:43 from being with Christ at death, yet who was told by the Lord that he would be with Christ in Paradise that day. And likewise imperfect Paul, (Philippians 3:13) who attested that to be absent from the body was to be present with the Lord. (2 Corinthians 5:7; cf. Philippians 1:23) And indeed it would exclude all believers who were told that they would be forever with the Lord if He returned in their lifetime (1 This. 4:17) though they were still undergoing growth in grace, as was Paul. 

In contrast, wherever Scripture clearly speak of the next conscious reality for believers then it is with the Lord, (Lk. 23:43 [cf. 2Cor. 12:4; Rv. 2:7]; Phil 1:23; 2Cor. 5:8 [“we”]; 1Cor. 15:51ff'; 1Thess. 4:17) 

And rather than Purgatory conforming souls to Christ to inherit the kingdom of God, the next transformative experience that is manifestly taught is that of being made like Christ in the resurrection. (1Jn. 3:2; Rm. 8:23; 1Co 15:53,54; 2Co. 2-4) At which time is the judgment seat of Christ And which is the only suffering after this life, which does not begin at death, but awaits the Lord's return, (1 Corinthians 4:5; 2 Timothy. 4:1,8; Revelation 11:18; Matthew 25:31-46; 1 Peter 1:7; 5:4) and is the suffering of the loss of rewards (and the Lord's displeasure!) due to the manner of material one built the church with. But which one is saved despite the loss of such, not because of. (1 Corinthians 3:8ff) 

Note also that the tradition-based Eastern Orthodox reject RC Purgatory, among some other substantial RC distinctives  

In addition, the whole premise that suffering itself perfects a person is specious, since testing of character requires being able to choose btwn alternatives, and which this world provides. Thus it is only this world that Scripture peaks of here development of character, such as "Wherein ye greatly rejoice, though now for a season, if need be, ye are in heaviness through manifold temptations." (1 Peter 1:6) The Lord Jesus, in being "made perfect" (Hebrews 2:10) as regards experientially  "in all points tempted like as we are, yet without sin" (Hebrews 4:15) was subjected to this in the life.

Meanwhile the salvation by holiness via baptism and purgatory are all under the RC rubric of salvation by grace thru merit: 

The theological virtues are the foundation of Christian moral activity; they animate it and give it its special character. They inform and give life to all the moral virtues. They are infused by God into the souls of the faithful to make them capable of acting as his children and of meriting eternal life. (CCC 1813 ) 

Moved by the Holy Spirit, we can merit for ourselves and for others all the graces needed to attain eternal life, as well as necessary temporal goods. (CCC 2027) 

"nothing further is wanting to the justified [baptized and faithful], to prevent their being accounted to have, by those very works which have been done in God, fully satisfied the divine law according to the state of this life, and to have truly merited eternal life." (Trent, Chapter XVI; The Sixth Session Decree on justification, 1547) 

"If anyone says...that the one justified by the good works that he performs by the grace of God and the merit of Jesus Christ, whose living member he is, does not truly merit...the attainment of eternal life itself and also an increase of glory, let him be anathema." (Trent, Canons Concerning Justification, Canon 32. 

The term “merit” refers in general to the recompense owed by a community or a society for the action of one of its members..., (Catechism of the Catholic Church, #2006) 

Note however, that,

"With regard to God, there is no strict right to any merit on the part of man," "the merit of good works is to be attributed in the first place to the grace of God, then to the faithful. Man's merit, moreover, itself is due to God, for his good actions proceed in Christ, from the predispositions and assistance given by the Holy Spirit." (CCC 2007-2008) 

However, this argument could be used for those who held to salvation under the Law, that by the grace of God they attained unto perfect obedience (and Paul as a Pharisee was blameless as concerning this: Philippians 3:6), whereas salvation by grace does not mean salvation by attaining to actual, practical perfection in this life or in Purgatory, but that of being accepted in the Beloved on His account, (Eph. 1:6) resulting finally in the resurrection of the body, which is the final conformity to Christ after this life. (1 John 3:2)  And with obedience with holiness in this life being its effects/fruits, but which effects are not the cause of justification, though works justify one as being a believer. (Heb. 6:9,10) 

And while God does reward faith (Hebrews 10:35) by rewarding the obedience of faith, (Mt. 25:31-40) and which obedience attests that one is a believer and thus it is appropriate that they be blessed, (Rv. 3:4) yet the "worthiness" here is not because moral attainment itself has made such accepted in the Beloved, and made them to sit together with Christ in Heaven,(Eph. 1:6; 2:6) and given them access to into the holy of holies in Heaven to pray, (Heb. 10:19) but as in conversion, it is because the faith that effects obedience is imputed for righteousness, (Rm. 4:5) eternal life being a gift, not a wage, (Romans 6:23) but in His grace God rewards the obedience of faith. (Heb. 10:35) Thus believers are exhorted, "Cast not away therefore your confidence, which hath great recompence of reward." (Hebrews 10:35) 

Moreover, the Catholic emphasis upon merit as obtaining eternal life not only leads to salvation via obtaining perfection of heart in this life or in mythical Purgatory, but it fosters just what the natural man expects, that if he does more good than evil then he can obtain Heaven. As expressed by this RC: 

I feel when my numbers up I will appoach a large table and St.Peter will be there with an enormous scale of justice by his side. We will see our life in a movie...the things that we did for the benefit of others will be for the plus side of the scale..the other stuff,,not so good will..well, be on the negative side..and so its a very interesting job Pete has. I wonder if he pushes a button for the elevator down for the losers...and what .sideways for those heading for purgatory..the half way house....lets wait and see.... ” http://forums.catholic.com/showpost.php?p=4098202&postcount=2
One should not assume RCs know what Scripture or their church teaches on this or that the two fundamentally conflict, and that distinctive Catholic teachings are not manifest in the only wholly inspired substantive authoritative record of what the NT church believed (including how they understood the OT and gospels), which is Scripture, especially Acts thru Revelation.

See more on Purgatory vs. Scripture here, by the grace of God.

The redeemed are those who have been spiritually born of the Spirit (Jn. 3:2-7) by effectual, penitent, heart-purifying, regenerating faith in the Divine Son of God sent be the Father to be the Savior of the world, (1 Jn. 4:14) who saves sinners by His sinless shed blood, on His account.

And which faith is imputed for righteousness, (Romans 4:5) and which is shown in baptism and following the Lord, (Acts 2:38-47; Jn. 10:27, 28) whom they shall go to be with or His return (Phil 1:23; 2Cor. 5:8 [“we”]; Heb. 12:22, 23; 1Cor. 15:51ff'; 1Thess. 4:17)

In contrast to those who were never born of the Spirit or who terminally fall away. (Gal. 5:1-4; Heb. 3:12; Heb. 10:25-39) Glory and thanks be to God.