And don't the Orthodox teach that too? At any rate, St. John Chrysostom seemed to think so:
Speak now, speak, let us listen. In the end of your work about which we now think upon, that is, in the newest part of the fourth book, "Saint John" - you say - "of Constantinople denies that original sin is in infants. As you see in this homily, he holds this about the baptized: 'Blessed' - he says - 'God who alone made miracles, who alone made the universe, and converts the universe. Behold how they are brought home to the serenity of liberty who were held a short time before as captives, and that they are citizens of the Church who were in the error of wandering, and that they are made just in lot who were in the confusion of sin. For they are not only free, but also holy, not only holy, but also just, not only just, but also sons, not only sons, but also heirs, not only heirs, but also brothers of Christ, not only brothers of Christ, but also co-heirs, not only co-heirs, but also members, not only members, but also a temple, not only a temple, but also organs of the Spirit. You see how many are the benefits of Baptism: and let no one think that the celestial grace consists only in the remission of sins: we however have computed ten honors. For this reason we also baptize infants; although they are not contaminated by sin, in order that holiness, justice, adoption, heredity, and the brotherhood of Christ may be added to them, and so that they may be his members'". ... I put the very Greek words themselves which were said by John: Dia touto kai ta paidia baptizomen kai toi amartemata ouk ekonta which is in Latin: "And therefore, we baptize infants, altough not having sins". You certainly see that "infants are not polluted by sin" is not said by him, but rather "sins" or that "they do not have sins": Understand rightly, and there is no contention. (St. Augustine, Against Julian, Defender of the Pelagian Heresy, Book I, 6, 21-22)
In the Orthodox Church, we still baptize infants for the same reason -- as we baptize all people: to bring them into the Church, where they can grow in the faith.
For it is wholly immaterial at which time you come into the church; every new patized Christian is a "spiritual infant." Baptism is a form of exorcism, where the new member is given the opportunity, through this sacrament, to renounce the devil and accept Christ. It's our accpetance of Christ that gives us a chance to cooperate with His Grace.
We hold that the reason we are outside of church when we are born is because of our fallen nature, for which our ancestral parents were responsible. We broke away from God's life-giving energy and died. God did not deprive us of His Grace. We did.
The reason I said that Latins teach that God deprives us of Grace is because of the Immaculate Conception. In this instance, God chooses to infuse Mary with Grace at the moment of her conception, which makes her a stranger to sin but does not change her human nature. In other words, she was destined to theosis by God's own doing, and not of her own free will.
The only thing we can conclude, assuming the IC is correct, is that God by His own will deliberately depirves the rest of us of His Grace as He deliberately infused mary with it.
If the Latin Church denies that God deliberately filled Mary and deprives others of His Grace, then the IC was an accident, and not an act of God.
+John Chrysostomos didn't teach this, from the Baltimore Catechism:
" Q. Why is this sin called original?
A. This sin is called original because it comes down to us from our first parents, and we are brought into the world with its guilt on our soul.
49. Q. Does this corruption of our nature remain in us after original sin is forgiven.
A. This corruption of our nature and other punishments remain in us after original sin is forgiven. "
If Blessed Augustine is saying that +John Chrysostomos believed in what the Latin Church now calls Original Sin, +Augustine was wrong (and as we all know, he didn't understand, or least understand it well). I'm seeing a pattern here.