Once humanity puts their mind to something, we’re capable of anything. We’ve cured mortal diseases, flown high above the clouds and thrown our creations far into the depths of space - just because we can. In that sense, we’re vastly more powerful than a so-called god.
But just like we’re capable of godly creations, we’re capable of biblical destruction the likes of which were never thought possible just a few centuries ago. Perhaps an autocrat ordered us to kill others in the name of the country he - oh so kindly - rules. Perhaps one of them did something we disliked. Who knows how it all started, now we’ve found ourselves in a situation where mercilessly killing others is justified.
Of course it’s justified. They’re not like us, they don’t have feelings and a family to return to at the end of the day. They don’t dream of a peaceful future. There’s no spark in their eyes when something they enjoy doing is brought up. You won’t see pain in those eyes either, staring into them as you’re forcing a weapon deep into their chest.