Day 172: What Does Baptism Do?

The different effects of Baptism are signified by the perceptible elements of the sacramental rite. Immersion in water symbolizes not only death and purification, but also regeneration and renewal. Thus the two principal effects are purification from sins and new birth in the Holy Spirit. CCC 1262

Today's reading in the Catechism is about the effects of Baptism. The Catechism Compendium summarizes this:

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). (#263)

I like how the Catechism ends this section by saying, "the whole organism of the Christian's supernatural life has its roots in Baptism" (CCC 1266).

The Catechism Companion, Vol II also has some good insights into this:

Every person who lives on this earth is a beloved creature of God. But something has to change in us and our human nature in order for us to actually be sons and daughters of God. We have to "become partakers of the divine nature" (2 Peter 1:4). When we receive the Holy Spirit in Baptism, God changes our nature. We become a new kind of being... Now in the New Covenant, we can call God "Father" because he has adopted us. (p. 108)

Amazingly, many in the early Church would delay Baptism, even though it is essential for Christians and we don't know the day or hour of our deaths. The Church urges us to be baptized as soon as possible after birth. The price that was paid was costly (Jn 3:16), one for which we should always be grateful. God really does love us that much.

Nicodemus seeks Jesus by night by Alexandre Bida (1875)

Jesus spoke to Nicodemus about the mystery of Baptism, by which we are spiritually reborn and made new creations in Christ (see CCC 1265; John 3:1-30). (p. 109)