They honestly think they are so "advanced" as to be untouchable.
They think their reign will last forever.
They are fools who don't know their history.
All those civilizations that thought of themselves as "beyond" base humanity found themselves ground in the dirt by the hooves of the barbarian's horses.
And it will happen again.
Evil is easy to spot if we are following the Lord's commandments and loving Him. Just follow instincts -- let Him work through you.
That's how to win a Holy war.