1) God is omnipotent.
2) God could not free the Jews in Exodus, without killing children.
God went on huge killing sprees in the old testament when he was in his 4000 year old bad mood of rage and smoting - Was it PMS perhaps - Pre Messiah Syndrome? You would have thought he'd have been in a worse mood after his creation nailed up his favourite son to a big T... T for trouble! But nah, we're all forgiven because of that awesome sacrifice, however that works.
Before he got all lovey dovey and nice he racked up a pretty huge body count. The guy on the following website estimates 2,270,365 dead in his moody acts of genecide.
Bible body count
And god has no problem killing babies and children and innocent bystanders. The crazy part is that Christians have trained themselves to gloss over this baby killing aspect of God. Some might even be reading this sentence in their minds with a delete key tidying up the mess as they go. They either throw it into their brain's recycle bin or they condone the mass baby killing as the act of something they believe is infinitely more wiser than we.
"All the little cute bundles of widdle biddie joy.. giggling and goo-gaaing. Slaughtered at God's command. Slaugtered and spared not!" - ... okay.. press erase... ...now!
The New testament writers jumped on this bandwagon and thought.. "Well, God doesn't have a problem killing babies, let's write in a son for him, (an only son- they Jumped the shark on this one to get more readers) let's have him.. ummm... allow his only son to die.. no no.. don't write off the character forever.. just have him die for a few days.