When looking at this system as a whole, it is clear that the salvation of the Roman Catholic is tied up in their church membership. The normative means for obtaining (and maintaining) the grace to merit salvation is through the church-provided sacraments.
”The sacraments, instituted by Christ and entrusted to the Church, are efficacious signs of grace perceptible to the senses. Through them divine life is bestowed upon us. Compendium of the CCC, #224
The Sacraments have been instituted as a special means through which we are to receive the grace merited for us by Christ. As Christ is the giver of the grace, He has the right to determine the manner in which it shall be given, and one who refuses to make use of the Sacraments will not receive God's grace. Baltimore Catechism #580
The sacraments are not just signs of something sacred, but actually give grace to the recipient. As such, the sacraments are considered necessary for salvation.
"The outward sign is not used merely to indicate that grace has been given, for the use of the outward sign with the proper intention also gives the grace of the Sacrament. Hence the right application of the outward sign is always followed by the gift of internal grace if the Sacrament be administered with the right intention and received with the right dispositions." Baltimore Catechism #584
"For believers in Christ the sacraments, even if they are not all given to each of the faithful, are necessary for salvation because they confer sacramental grace, forgiveness of sins, adoption as children of God, conformation to Christ the Lord and membership in the Church." Compendium of the CCC, #230
Through the sacraments Catholics are initiated into the Church and into Christ. This initiation usually begins with the Baptism of an infant followed later by Confirmation between the ages of seven and sixteen (USCCB).
”Christian initiation is accomplished by means of the sacraments which establish the foundations of Christian life. The faithful born anew by Baptism are strengthened by Confirmation and are then nourished by the Eucharist.” Compendium of the CCC, #251
”Baptism is a Sacrament which cleanses us from original sin, makes us Christians, children of God, and heirs of heaven… We are the heirs of Christ because at His death we came into the possession of God's friendship, of grace, and of the right to enter heaven, provided we comply with the conditions Our Lord has laid down for the gaining of this inheritance. The conditions Our Lord has laid down for the gaining of this inheritance are: That we receive, when possible, the Sacraments He has instituted; and that we believe and practice all He has taught.” Baltimore Catechism #621, 624, 625
”Born with a fallen human nature and tainted by original sin, children also have need of the new birth in Baptism to be freed from the power of darkness and brought into the realm of the freedom of the children of God, to which all men are called. The sheer gratuitousness of the grace of salvation is particularly manifest in infant Baptism. The Church and the parents would deny a child the priceless grace of becoming a child of God were they not to confer Baptism shortly after birth.” CCC 1250
”Baptism is the sacrament of faith. But faith needs the community of believers. It is only within the faith of the Church that each of the faithful can believe... CCC 1253
Obviously an infant does not have a faith in Christ in Baptism so the parents are expected to make the profession of faith.
”Everyone who is to be baptized is required to make a profession of faith. This is done personally in the case of an adult or by the parents and by the Church in the case of infants. Also the godfather or the godmother and the whole ecclesial community share the responsibility for baptismal preparation (catechumenate) as well as for the development and safeguarding of the faith and grace given at baptism.” Compendium of the CCC, #259
After receiving the sacrament of baptism, the recipient becomes “a new creature” and belongs forever to Christ. Through baptism is given the grace of Justification.
"Baptism takes away original sin, all personal sins and all punishment due to sin. It makes the baptized person a participant in the divine life of the Trinity through sanctifying grace, the grace of justification which incorporates one into Christ and into his Church. It gives one a share in the priesthood of Christ and provides the basis for communion with all Christians. It bestows the theological virtues and the gifts of the Holy Spirit. A baptized person belongs forever to Christ. He is marked with the indelible seal of Christ (character)." Compendium of the CCC, #263
"The Most Holy Trinity gives the baptized sanctifying grace, the grace of justification:
- enabling them to believe in God, to hope in him, and to love him through the theological virtues;
- giving them the power to live and act under the prompting of the Holy Spirit through the gifts of the Holy Spirit;
- allowing them to grow in goodness through the moral virtues.
Thus the whole organism of the Christian's supernatural life has its roots in Baptism." CCC 1266
If the baptized "falls" from grace through mortal sin, they must re-establish their grace through the sacrament of penance. Hence, the ability to remain in grace requires continuing in the church system not only to access penance, but also to increase grace through the eucharist and the mass to protect from falling into mortal sin in the first place.
Such is the sacramental road to salvation.
"For freedom Christ has set us free; stand firm therefore, and do not submit again to a yoke of slavery." Galatians 5:1