Trust and intimidation
As I pondered this, I realized it explains quite a few things. It's certainly why we clothe ourselves with violence, expecting violence to protect us. It's why Lamech the son of Cain made sure to avenge himself 77 times by killing someone for striking him, who had probably struck this arrogant man for wronging him, as such people feel entitled to do.
We can never make God afraid of us, and that's why we'll never trust Him if we think like this. Failing to trust him always makes us trust in other things which end up killing us, and so our reliance on fear to make people compliant and therefore trustworthy ensures that we perish.
So then the saying proves true, "Whoever lives by the sword will die by it" - at the very moment that, as the world counts it, he is achieving success.