It's a tough question, but I think it can be effectively reasoned out with scripture, even though there is no specific statement that says that all innocent children go to heaven, followed by a defining of that innocence.
First of all, Jesus said "suffer the little children to come unto Me, for such is the kingdom of heaven." He also said that unless we become like children, we'll have trouble entering that same kingdom. Since he used the literal example of the kids the diciples were trying to shoo away, I take this in a literal sense to some extent as well as the obvious spiritual. Especially if you consider the obvious level of love that God has for children, speaking of it often in the Old and New Testaments. Anyway, what He meant was that their innocent, trusting, unconditional "I believe whatever you tell me" hearts of faith are exactly what God wants from us.
Also, and this is a pretty broad example, so be kind. :) But it has always struck me that when God disallowed the men of Israel to enter Canaan after fearing the Canaanites described by the scouts' report, He drew the line at the age of 19. Any man over that age had to stay behind. Now, I don't think that all men under the age of 19 are innocent - hardly - but I think this example is an interesting point to ponder, that God did not consider those young men party to their elders' sin.
With specific regard to abortion, God tells Jeremiah that before he was born, God had plans for him. In Psalm 139, which happens to be my favorite, David says that God knew all about him in the womb, that He formed all his parts, knew all his days before any were lived. In my opinion, God of course then knows which babies will never make it out of the womb, and a just and loving God cannot send those souls to hell. Also, when David's son by Bathsheba dies after only living a few days, David says that one day he will go to him. David knows that he and his son will be reunited one day -
2 Samuel 12:23 But now he is dead, wherefore should I fast? can I bring him back again? I shall go to him, but he shall not return to me.
Just some quick references from my random thoughts, there are certainly more, but I believe wholeheartedly that a strong scriptural argument can be made for the acceptance of babies and small children.
Agrace!!! Good summary of the basis of many of the things you claim Catholics believe are not scriptural,
i.e., GOD gave us a brain AND the HOLY SPIRIT, and the promise that the gates of Hell would not prevail, and Scripture, and promised the Holy Spirit would lead us to all Truth, and that not all things are recorded in scripture...
it can be effectively reasoned out with scripture,[under the inspiration of the Holy Spirit by the authority Christ bestowed on Peter and His church] even though there is no specific statement that says
all the things you claim we believe are unscriptural...
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