Baptism is an outward sign of faith. In the case of infant baptism, it is really the parents who are confessing Christ, dedicating the life and upbringing of their child to Him, and asking God to send His Spirit upon the child. (My brother's church actually calls this "dedication" rather than baptism.)it is good to dedicate our children to the Lord, but it is not the same as baptism
To delve deeper into the Word to illustrate the importance of baptism as an outward sign of faith:
He who believes and is baptized will be saved; but he who does not believe will be condemned (Mark 16:16). This verse makes it clear that belief in Christ is the determining factor. Baptism is important as a sign of submission to the will of God. But what is most important is the state of one's heart.
I'm a Catholic, but not a very good one (being brought up Lutheran)... I know that infant baptism and other sacraments appear as though they are man-made "works" that we say are necessary for salvation. But what I was taught in becoming Catholic was that the validity of any sacrament is fully dependent upon the state of the recipient's heart; if I really do not believe in Christ then it matters not what actions I perform, as I will not receive grace regardless of whether I go through the motions. Now this brings up a tough question, as when we baptize an infant, the point is for the infant to be the recipient of grace through the sacrament; but how can we know the state of a infant's heart? Does it all depend upon a person reaching the age of reason? And who therefore is responsible for the child's state of grace prior to that age?
So then, what about infants? Who knows the state of their heart but God? Does baptism actually save an infant? Is an infant capable of believing? What if children die before reaching the age of reason, whether baptized or not, if they cannot confess Christ while alive on this Earth, will they go to Heaven or Hell?
I look to the following verse as offering hope that any child who dies before the age of reason is welcomed into Heaven by our Lord with open arms:
Truly, I say to you, unless you, unless you turn and become like children, you will never enter the kingdom of heaven. Whoever humbles himself like this child is the greatest in the kingdom of heaven. (Matthew 18:3-4)