I'm not clear on just how a religion that teaches that God doesn't really desire you to sacrefice your first born, is a bad thing. Yes, saying that you should be willing to do things you find morally abhorent, if your God requires them of you, is a rather primative moral code, a bad thing, and all that. However if you take the account as factual, God stopped Abraham before he went through with it. Abraham was living in a place where other religions did practice infant sacrefice (if that part of the OT is also factual - and note that most modern archaeologists and historians don't dispute that part regardless of their own religious affiliations). If it wasn't Yahway telling him to do it, Abraham would have had the example of other religions suggesting it was the right thing to do - and if Abraham or others had been inspired just by those examples, the various Bels and Marduks and such of the region, what would have stopped them from following it all the way through? The old testament version of God at least says, in effect "Yeah, I'm expecting obedience just like every other single god you've even remotely heard of, but now I'm gonna show you I'm more worthy of that obedience than those gods, because there are things I won't ever ask you to do, because I care about you and yours too much to ask them of you". The parable of Abraham is about a supposed deity saying He's not just expecting BLIND obedience, He's willing to give some sign of why He should actually deserve obedience. Yes, (some) more modern versions of religions have gotten to a lot better moral theory than that, but it was still a small step in the right direction.
While were at it, criticising Islam or at least its founder, sort of depends on the situation. There's a certain difference if the prophet created teachings to justify his taking a child bride, or if that was the way things still worked in the region, at that time, and he just didn't behave to a higher standard than the secular society immediately pre-islam. Most of the people throwing out the pedo-prophet charge have no idea if the actions of Mohammed were any worse than typical for the parent culture, or about average, or even a bit better, and it may be that the worst claim to be leveled against Islam is it didn't make the people who joined behave to a higher standard than they would have otherwise.
The modern Roman Catholic church has failed dramatically, becoming one of the safest places for child molesters to hide. Unlike the 9th century, the current church is operating against a background of secular cultures who overwhelmingly have clear laws specifying a minimum age of consent, and just about all of those cultures
set that age at at least 14 for any sexually related activity and 16 or higher for some forms. It's actually less explicable than the ancient examples.