What does baptism do? We know through Scripture that baptism makes us members of the Body of Christ. “For in one Spirit we were all baptized into one body, whether Jews or Greeks, slaves or free persons, and we were all given to drink of one Spirit.” (1 Cor 12:13)
Baptism brings us in communion with each other by becoming members of the One Body of Christ.
For all of you who were baptized into Christhave clothed yourselves with Christ.
We are brought into the Body of Christ, the Church.
And he is the head of the body, the church(Col 1:18)
And God placed all things under his feet and appointed him to be head over everything for the church, which is his body, the fullness of him who fills everything in every way. (Eph 1:22-23)
Since we are baptized into the one body of Christ and we now know that Christ’s Body is the Church means that baptism brings us into the Church. And this is why there is no salvation outside the Church because there is no salvation outside of Christ.
Baptism is the New Covenant fulfillment of the Old Covenant symbol of circumcision. As the Hebrews circumcised those for entrance into God’s Covenant with Israel, so too does the New Covenant fulfillment of circumcision bring entrance into the New Covenant of God to His Church through baptism.
In him you were also circumcised with a circumcision not administered by hand, by stripping off the carnal body, with the circumcision of Christ. You were buried with him in baptism, in which you were also raised with him through faith in the power of God. (Col2:11-12)
If eight-day old children could enter the Old Covenant through circumcision via the faith of their parents how much more so can infants become adopted children of God through the New Covenant circumcision, baptism? The New Covenant is much more inclusive than the Old seeing as the New can include the gentiles as opposed to those of the line of Abraham.
We have seen that baptism fulfills the Old Covenant practice of circumcision (Col2:11-12). Baptism was prophesied by Ezekiel to bring graces through the sprinkling of water (Ez 36:25-27) and washes away sins (Ez 36:26; Acts 2:38).
What else is baptism for? Well, is baptism necessary for salvation? The answer, very plainly is YES. “…eight in all, were saved through water. This prefigured baptism, which saves you now.” (1 Pet 3:20-21). Pretty simple. As plain as it can get. Jesus taught this also in the Gospel of John
“Jesus answered and said to him, “Amen, amen, I say to you, no one can see the kingdom of God without being born again.” Nicodemus doesn’t understand and so Jesus repeats himself, He says “Amen, amen, I say to you, no one can enter the kingdom of God without being born of water and Spirit.
One is born again through baptism, and that through baptism one can enter the kingdom of God, the Church…
And so we see that baptism brings Graces from God (Acts 2:38), washes away sins (Acts 2:38), we enter into a covenant with God through baptism (Col2:11-12), we become Christians through baptism (1 Cor 12:13) by becoming members of the Church as through a door (Eph 4:4). And baptism is instituted by Jesus Christ when He sent out the disciples to “Make disciples of all nations, baptizingthem in the name of the Father, and of the Son, and of the holy Spirit, teaching them to observe all that I have commanded you.” (Mat 28:19)
Please take the time to read what the Early Church believed about baptism and you’ll find a unanimous consensus on baptismal regeneration and the acceptance of infant baptism.