Is the serpent in Genesis 3 just a snake or Satan? Does the Hebrew refer to "the satan" or "Satan"? And does it make a difference? Let's take a look at the Old Testament, early Jewish literature, and the New Testament for the answers.
With regard to evil, your objective is not merely to tempt humans to do bad things. Yes, of course, there is profit in theft and adultery and such, but only if you follow through to the next step.
When Jesus was baptized, his Father’s voice fell from heaven, proclaiming, “You are my beloved Son, whom I love; with you I am well pleased,” (Mk 1:11). But there in the wilderness it did not seem so, did it?