Some liberal Christians view the charachter of Satan as being a symbol for the evil within humans which tempts us all. The JWs will often point to Jesus being tempted by Satan as being proof that this is an unreasonable explanation since "Jesus was perfect and he could not have evil thoughts in him." Now this raises a conumdrum for a similar, but related matter.
Just what can a perfect person do or not do when it comes to "sinful" thoughts? The above explanation, oft quoted by JWs, makes it appear as if a perfect being cannot even be tempted by wicked thoughts which arise in oneself, in fact, they would not have any such cognition. Okay, so how could sin start at all? If it is not even possible for a perfect being to think sinful thoughts, how does one eventually sin? Also, is it a temptation if you do not actually desire what is put before you (hence, a wrong thought)?
Expanding this further (this could go on forever!), what about those who are brought to heaven from the earth, according to the JW understanding? They say that they will inherit immortality (literally "deathlessness") which of necessity means not even being able to sin. So do they no longer have free will? Why not just create beings with this "deathless, sinless" state from the beginning?
Oh, I see I've strayed far off topic, forgive me. But it does lead to a lot of knotty problems, doesn't it?