Is it really appropriate to think of evil as a 'thing'? This is a difficult question, because evil does indeed seem so real to us - it is manifested everywhere in the world. On one level I agree - of course evil is real, it is a fundamental reality of our daily existence. But does evil have an ontological reality? Does it exist like goodness exists? These might seem like really quite abstruse theological questions, especially if you want to debate the existence or non-existence of Satan and his legions. You might just as well count angels on a pinhead! But if I understand Juschecking24 correctly, he is raising the objection that Augustine raised against the Manicheans: evil is ultimately just a "privation of good", a separation from the presence of God. For all its apparent power over us it is, properly understood, nothing at all. That's counter-intuitive, but also really hopeful I think. It recasts the struggle against sin as a struggle of radically unequal forces: it is not so much a human dilemma of choosing between two tempting options as it is God's real and present rejection of our human tendency to lapse into nothingness.

I think I disagree with some of the other things you add, but I'll leave it there.