So, if someone assents to the infused grace of baptism and cooperates with it, he or she is then in a state of grace, or justification. However, the grace that is received through infusion is by no means immutable. When Roman Catholics speak of their sacramental theology, they use quantitative terms with respect to grace, saying there can be an increase or diminution of it. In other words, a baptized person can lose some of his infused grace. In fact, it may be lost entirely, removing the person from a state of justification and putting him or her under the threat of damnation.
(CCC 1129) “The Church affirms that for believers the sacraments of the New Covenant are necessary for salvation. ‘Sacramental grace’ is the grace of the Holy Spirit, given by Christ and proper to each sacrament. the Spirit heals and transforms those who receive him by conforming them to the Son of God. the fruit of the sacramental life is that the Spirit of adoption makes the faithful partakers in the divine nature by uniting them in a living union with the only Son, the Savior.”
(CCC 1213) “Holy Baptism is the basis of the whole Christian life, the gateway to life in the Spirit (vitae spiritualis ianua), and the door which gives access to the other sacraments. Through Baptism we are freed from sin and reborn as sons of God; we become members of Christ, are incorporated into the Church and made sharers in her mission: ‘Baptism is the sacrament of regeneration through water in the word.'”
(CCC 1263) “By Baptism all sins are forgiven, original sin and all personal sins, as well as all punishment for sin. In those who have been reborn nothing remains that would impede their entry into the Kingdom of God, neither Adam’s sin, nor personal sin, nor the consequences of sin, the gravest of which is separation from God.”
(CCC 1285) “Baptism, the Eucharist, and the sacrament of Confirmation together constitute the ‘sacraments of Christian initiation,’ whose unity must be safeguarded. It must be explained to the faithful that the reception of the sacrament of Confirmation is necessary for the completion of baptismal grace. For ‘by the sacrament of Confirmation, [the baptized] are more perfectly bound to the Church and are enriched with a special strength of the Holy Spirit.'”
(CCC 1992) “Justification has been merited for us by the Passion of Christ who offered himself on the cross as a living victim, holy and pleasing to God, and whose blood has become the instrument of atonement for the sins of all men. 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. Its purpose is the glory of God and of Christ, and the gift of eternal life.”
(CCC 1999) “The grace of Christ is the gratuitous gift that God makes to us of his own life, 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. It is in us the source of the work of sanctification.”
The sacrament of baptism is the first sacrament that is administered to a person in the Roman Catholic Church. Rome holds that baptism conveys grace ex opere operato, and the grace that is conveyed by baptism is the grace of regeneration. This means that when a person is baptized, he is born again of the Spirit, and the disposition of his soul is changed, leaving him justified in the sight of God. Righteousness is “infused,” or poured into his soul. Rome then believes and teaches that the prerequisite of justification, the instrumental cause, is baptism. In Protestant theology, by contrast, the instrumental cause is faith, and God imputes righteousness to the believer.