Lucifer knows that Adam was reincarnated as a sinner in Hell. He first found him outside in an alley and told him he deserved whatever happened to him out there for all the shit he's done and walked away. Three months later he sees him again and they get to talking. "Are you sure you don't wanna stay out here? I see you've got a few friends waiting for you." He gestures at the sinners behind him who are stalking Adam like he's their prey.