The very word itself means "to submerge or immerse in water" so to say that immersion isn't necessary is to deny the meaning of the word.
baptize (baptizo) - Online Bible Study Tools
Still, it is an outward testimony of what has occurred within, and if one is not baptized it will not affect his salvation. But the one thing in my post you didn't deal with is the child's ability to make a decision. That remains as a stalwart argument against infant baptism, as someone who can't make the decision certainly can't testify about it.
I did deal with it. The parents and Godparents make the decisions for the child, just as they make the decisions for everything else in the child's life.
But if you would like to allow your children to do whatever they want however they want, so be it.
The Catholic Church has always understood baptism differently than Protestants (who cannot agree among themselves, either), teaching that it is a
sacrament which accomplishes several things, the first of which is the remission of sin, both original sin and actual sin.
Peter explained what happens at baptism when he said, "Repent, and be baptized
every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit" (Acts 2:38). But he did not restrict this teaching to adults. He added, "For the promise is to you
and to your children and to all that are far off, every one whom the Lord our God calls to him" (2:39). We also read: "Rise and be baptized, and wash away your sins, calling on his name" (Acts 22:16). These commands are universal, not restricted to adults.
We also know that Christian baptism is the replacement for the rite of circumcision, which was done to infants, mostly.
Immersion is not the only meaning of
baptizo. Sometimes it just means washing up. Luke 11:38 reports that, when Jesus ate at a Pharisees house, "the Pharisee was astonished to see that he did not first wash [
baptizo] before dinner." They did not practice immersion before dinner, but, according to Mark, the Pharisees "do not eat unless they wash [
nipto] their hands, observing the tradition of the elders; and when they come from the market place, they do not eat unless they
wash themselves [
baptizo]" (Mark 7:34a). So
baptizo can mean cleansing or ritual washing as well as immersion.
A similar range of meanings can be seen when
baptizo is used metaphorically. Sometimes a figurative "baptism" is a sort of "immersion"; but not always. For example, speaking of his future suffering and death, Jesus said, "I have a baptism [
baptisma] to be baptized [
baptizo] with; and how I am constrained until it is accomplished!" (Luke 12:50) This might suggest that Christ would be "immersed" in suffering. On the other hand, consider the case of being "baptized with the Holy Spirit."
In Acts 1:45 Jesus charged his disciples "not to depart from Jerusalem, but to wait for the promise of the Father, which, he said, you heard from me, for John baptized with water, but before many days you shall be baptized with the Holy Spirit." Did this mean they would be "immersed" in the Spirit? No. Three times Acts 2 states that the Holy Spirit was
poured out on them when Pentecost came (2:17, 18, 33)
I hope I've answered your question thouroughly enough.
Baptism is not only