We’re saved apart from Baptism. Baptism is only a public expression of faith.
Why then does First Peter 3:21 say, "[Your] baptism … saves you now"? And why does Titus 3:5 say, "He saved us through the bath of rebirth and renewal by the Holy Spirit"?
Why do Catholics baptize babies when babies can't speak for themselves?
In the Gospels, John the Baptist receives the Holy Spirit while still inside his mother's womb (Luke 1:15). ... Baptism is not something we do; it's something God does to us. Salvation is a free gift from God, which cannot be earned. Nothing illustrates this truth better than Infant Baptism. Like the paralytic in Matthew 9, the baby is unable to walk on his own and has to be carried to Jesus by others. Like Jairus' daughter (in the same chapter), who was brought back to life, not by her own faith but by the vicarious faith of her parents, the baby is unable to speak for himself; the Church must speak for him. … Later he’ll be required to make his own personal statement of faith. We call that Confirmation.
Babies have no sin; they don’t need to be baptized.
True babies can't commit actual sins, but they are born with Original Sin, the sin of Adam and Eve, which must be washed away. Psalm 51:7 says, "I was born guilty, a sinner, even as my mother conceived me." To say that babies don't need to be baptized is really to say they don't need to be saved—they don’t need a Savior!
Read more about Baptism in the Catechism of the Catholic Church.
Baptism should be by immersion, not pouring.
Where does the Bible say that? … Moreover, how did the Apostles dunk the three thousand who were baptized on Pentecost? There’s no body of water in Jerusalem large enough to do it! ... Or what if you were evangelizing Eskimos in the Arctic Circle. Would you dunk them?
The Catholic Church teaches that unbaptized babies go to hell.
Some Catholics may have thought that way in the past, but that was never an official doctrine of the Church. Because God is all-merciful, we can be sure He provides unbaptized babies a way to be saved, though how He does it is a mystery because He hasn't revealed it to us. That’s an extraordinary case, though, and it’s wrong to argue from the extraordinary to the ordinary. Ordinarily, babies have the opportunity to be baptized and it would be wrong to withhold sanctification from them. Remember Jesus said, "Let the little children come to me and do not forbid them" (Matt. 19:14).
But if unbaptized babies go to heaven, why bother baptizing them?
In Colossians 2:11-12, Paul identifies Baptism as the fulfillment of circumcision. Circumcision was the rite of initiation into Israel according to the Old Covenant and was performed on infants. Baptism is the rite of initiation into God’s family according to the New Covenant. Given that the old rite was performed on babies, doesn’t it make sense that the new rite should be as well? … Moreover, if Baptism is the ordinary entryway into the family of God, isn’t it best for one to be baptized at the start of life? Why delay entry into God’s family?