- The innocent should go to heaven.
- Newborn children are innocent.
- No one who dies before being baptized goes to heaven.
- Therefore, newborn children don't go to heaven even though they are innocent. But this is a contradiction. So one of the premises or underlying assumptions must be wrong.
A simpler (and to my mind preferable) solution would be to give up the ideas of innocence, baptism, and heaven entirely. They may be comforting stories one can tell oneself, but as the preceding shows they don't really work as rigorous thought.
I wonder how much mental energy has been devoted to attempting to deal with issues of this sort.