Again, I just offered my own thoughts on the children at the rapture of the church. I could be wrong.
It was an excellent response, in my view.
The idea of the "innocence" of babes and children is repulsive to those who take the position that sin is a disease inherited from their parents, and among some it is absolute blasphemy. But I agree with you, because many that take that view also feel one must have heard the Gospel and placed faith in Christ within their lifetime in order to go to Heaven. One problem with that position is that we have an entire Old Testament filled with just men and women who, because the Gospel of Christ had not been revealed to them, lived and died without ever receiving an understanding of Who the prophecies Messiah was and what He would do.
And it is on this basis that I look to the grace of God in regards to those who die while yet in the womb, and even at young ages. God consistently judges men throughout Scripture according to the Revelation they have received, and their response to that revelation. That is why the Writer of Hebrews makes a distinction between the judgments of those who had received the Law, and those who had received the Gospel:
Hebrew 10:28-29 KJV
28 He that despised Moses' law died without mercy under two or three witnesses:
29 Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?
I do not consider children "innocent" because they have not sinned, but simply because they are conceived, like David, under the conditions of sin. Their problem is not that they have "inherited sin," but that they are separated from God. So too were the Old Testament Saints, and they died waiting to be made complete in regards to remission of sins:
Hebrews 11:13 KJV
13 These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them, and confessed that they were strangers and pilgrims on the earth.
Hebrews 11:30-40 KJV
39 And these all, having obtained a good report through faith, received not the promise:
40 God having provided some better thing for us, that they without us should not be made perfect.
So if these men and women can grow up, sin (grievously in some cases), and die before they were made complete (perfect) in regards to remission of sins (Hebrews 10:1-4; Hebrews 10:10-14), and still receive the grace and mercy of God, why wouldn't we think God would bestow grace unto those who died in the womb having never had the chance to either sin or profess faith?
God bless.