People love their sin. Their deeds are evil. They are wicked. Christ is the light of the world, but people hate the light. Like cock roaches or rats, when the lights are turned on, they run for their holes.
People fear the light because it exposes their evil deeds.
But those who love truth and righteousness, come to the light and accept the gospel. So our first reason for people not becoming Christians is animosity toward God. Because they are wicked. People are godless and wicked. And they suppress the truth they know, by their wickedness.