This dufus is well aware that there is a God and that there is a Jesus, and chooses to HATE and REJECT them, and spread his vile message, hoping to have others submit to his view. In other words, he's jealous of the higher power that he can't control.
Most of the militant "atheists" that are out there fall into this bucket. They're not "non-believers"--They are hate-filled, jealous servants of evil, trying to convince themselves that there is no God so they don't have to be accountable for their actions on Earth. And because Christians confront them with this reality, the only way to prevent this confrontation is to stamp out any possibility that the truth of the Christian message be shown to them, so they don't have to answer their own conscience.