I think this kind of teaching errs in a couple of ways. First, the idea that every temptation, and every sin into which we fall by yeilding to temptation, is demonic, is rather a cop-out. It is an attempt to get us off the hook, so to speak, to remove any human responsibility or accountability. Therefore we have the demon of tobacco, for those who can't quit smoking. We have the demon of alcohol, or the demon of anything else to which we are addicted. We have the demon of lust, for the one who wants to blame anyone but himself for his problems in that area.
Second, this teaching can lead to huge burdens of guilt. Because we all know, or at least suspect, it to be wrong. Temptation does not cease the moment we come to faith in Christ -- and we all know it. But this teaching, for anyone who takes it seriously, means we can't admit it. If we are told that the moment we come to faith, our heaarts are basically pure, then the one who is tempted must think there is something wrong with him. "Why," he might cry, "can I not quit smoking? Why do I still have these feelings when I look at pretty women?"
They forget that the Bible tells us that, "The heart is deceitful above all things and beyond cure." (Jeremiah 17:9)
They forget that the Apostle Paul quite specifically admitted that he struggled with his own feelings in this area,
When I want to do good, evil is right there with me. For in my inner being I delight in God's law; but I see another law at work in the members of my body, waging war against the law of my mind and making me a prisoner of the law of sin at work within my members. What a wretched man I am! Who will rescue me from this body of death? (Romans 7:21-24)
But then he puts it into perspective, "Thanks be to God—through Jesus Christ our Lord!" (v25)
I was accused by a commenter on a previous post of demeaning humanity by referring to our wretchedness. But to me it is obvious. C.S. Lewis' idea of the natural moral law points it out well. We know what we should do, but our natural impulse is not to do it. We know it is right to be generous, but our nature is to be selfish. We know that some things we do are wrong, but we do them anyway -- and deliberately. It seems to me that anyone who holds that the human heart is basically good is just whistling past the graveyard, trying to ignore or deny something that, deep down, is quite apparent.
But in truth, the pressure is off. The burden of guilt is not ours to bear. Because, although we do not become perfect ourselves the moment we acknowledge Christ as our Saviour, at that moment his perfection is imputed to us. We are counted as perfect, in spite of our imperfection. The very first verse of the very next chapter, that pinnacle Chapter 8 of Romans says this;
Therefore, there is now no condemnation for those who are in Christ JesusWhat a relief! What a comfort! What a joy to know that, "Jesus Paid it all." Christ has done everything necessary for the salvation of all who believe in him.
Does this give permission for license? Not at all! As Paul himself says in Romas 6, verses 2&15, (depending on your translation) "By no means!" (NIV), "God forbid!" (NKJV), or in a new modern language, yet to be released, "Duh!" If we have come to Christ, Jesus is at once our brother, our Lord and our new best friend. Deliberate sin on our part is an expression of ingratitude for what he has done for us. It is to spit in his face. Why would we do it?
And thanks be to God for the assurance of 1 John 1:9,
If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.
What a relief it is to realize the reality of our own depravity; to realize that we need not bear the impossible burden of perfection. But how even greater a joy to know it will not be forever, because one day we will be like him and see him as he is, (1 John 3:2) and our sinful human nature truly will be, a thing of the past.