Evil in Heaven???

In my Hermeneutics class the other night, an intriguing conversation began as a result of a seemingly random tangent. I don't know what our professor had planned, but he allowed the tangent to dominate the rest of the evening.

The main idea being discussed was this: the presence of evil in heaven.

Two things shocked me about this at first:
1) I had never heard this theory before - I was shocked b/c it seemed so scandalous.
2) I was astonished how many other students already presupposed this theory.

I am in no way attempting to answer or argue anything here. I thought I'd simply recall a few statements and let you have your own fun with them.

- Goodness can only be considered good in light of the presence of evil, just as black could not be known as black if it were not juxtaposed with white. Therefore, if God is to be known as good(even in heaven), how could evil not have a presence?

- The presence of evil was presupposed in the Garden of Eden, the first "heaven" or paradise of sorts. Why would the new heaven be any different?

- Evil will have a presence, but it will have no power.

- Sin is a gift in the sense that the possibility of sin and the reality of our own sin drives us back to God. If our ability to sin is taken away, would we then be God? What is our functional need of God then? Sin is not our enemy. It's there to lure us, to invite us to repentance and the love of Christ.

- As we now see but a poor reflection as through a mirror, then we shall see and know fully. Evil will be present, but because of our knowledge, it will have lost its seduction.

My main question: The possibility of temptation presupposes the freedom to choose sin. Theoretically, then, could I choose to sin?

I think I would have serious problems with this theory, but as of now, I'm pretty ignorant on the whole thing. But I guess we're all ignorant. As my Hermeneutics professor said, "The only thing I know for certain about my theology is that it's wrong."