The story about the Devil tempting Jesus is clearly not comparable. IF Satan ACTUALLY appeared to people, many, many, many more people would decide not to do whatever bad thing it is that they're being tempted to do. However, God still created Satan. He created him, and allows him to exist, knowing that he's not only going to tempt people, but also knowing this his temptations are going to result in horrific things happening to people, the majority of which won't go to heaven, but will spend eternity being tortured in hell.... if you believe the New Testament version of the afterlife.