
   Romans 10:16-17 "But not all the Israelites accepted the good news.  For
   Isaiah says, 'Lord, who has believed our message?'  Consequently, faith
   comes from hearing the message, and the message is heard through the word
   of Christ."

   So then we receive God's gift of faith to us as we hear the message of the
   gospel.  Faith is a possible response to hearing God's word preached.  Kids
   are not yet spiritually, intellectually, or emotionally mature enough to
   respond to God's word.  Hence they cannot have faith and therefore cannot
   be raised in baptism to a new life.

Catholics view the effects of Baptism slightly differently, and that's
one primary reason why they baptize babies.  They believe that Baptism
produces a change in the soul of the baby, quite independently of any
volitional act on the part of the baby.  This change in the baby's
soul gives the infant certain capabilities that he would not have
without Baptism.  Since the infant does not have the use of his
intellect and will yet, these new faculties are dormant.  But as the
child gets older, the gifts of Baptism come more and more into play.

   Ezekiel 18:20 "The soul who sins will die.  The son will not share the
   guilt of the father, nor will the father share the guilt of the son.  The
   righteousness of the righteous man will be credited to him, and the
   wickedness of the wicked will be charged against him."

   If you read all of Ezekiel 18, you will see that God doesn't hold us guilty
   for anyone else's sins.  So we can have no original guilt from Adam.

Adam was given a number of gifts by God.  The chief among them was
what Catholics call "sanctifying grace".  (In the New Testament, the
word used for this is "charity".)  By his sin, Adam lost this grace.
He didn't lose it just for himself, however, he lost it for the whole
human race.  Because once he lost it, he couldn't pass it on to his
descendents.

That's why Catholics baptize babies.  Through his Original Sin, Adam
lost sanctifying grace for all his descendents.  Christ instituted
Baptism to give it back to everyone.