Lucifer is less the master of temptations, and the speaker of truths...
Lucifer: "Pssst...yo, snakey!"
Temptation: "Uh, what is it, boss?"
Lucifer: "I see god is keeping people in the dark again, and that don't fly with me. Go tell that human woman to eat that apple, also...maybe you should bed her or something. Her mate is positively boring her."
Temptation: "Erm...but, wouldn't giving them the knowledge of good and evil also make them aware of your presence? God may just raise them up to eventually get rid of you...?"
Lucifer: "Meh...I can deal with that when it happens, and I don't see it happening for a long time. God doesn't see the humans as anything, and thus they won't be anything, till I raise them up multiple times in sin."