God’s ways of communicating with people is slightly limited. He basically only has one method: You’ll hear it a voice in your head.
The next time a Christian challenges your atheism, challenge him back with this question: “Would you kill me if God ordered you to?”
If he says no, apparently he doesn’t trust God’s word. Or he’s lying.
If he says yes, you know you’re dealing with a dangerous person who will obey a voice in his head. But at least he’s honest about his harmful belief.