You need to understand that there was an age before this one that we all lived in (not in the flesh, there is no reincarnation) but that we can't remember. Satan rebelled and 1/3 of the souls created aligned themselves with Satan to take over God's throne. So when you see that God tells the Israelites to go across the countryside and whoop butt in the Old Testament, the people taking the butt-whooping probably did something to deserve it in the first age. It makes sense why the family of Adam would be God's chosen also. If you were God and you were going to run your 12 billion or so souls through this test in this age, you would do the ones that stuck with you a favor and let them be amongst each other and you would favor them most of the time and let them have their way as long as they were behaving.
So the little babies whose throats were slit by Joshua, had it coming...?
They deserved it?