Let me suggest to you that we can live perfect lives. Now that may sound like the most outrageous thing you have ever heard, because one of the few things you'll get both Christian and non-Christian to agree on is that nobody is perfect!
What the New Testament teaches, as I understand it, is that once the Holy Spirit comes into my life, once I'm indwelt by the Holy Spirit, I have living within me the power to obey God. The Holy Spirit gives me the power to obey the commandments of God, and the New Testament says there is no temptation that has ever befallen me that isn't common to every person, and with the temptation God always provides a way of escape. I don't think anybody does, in fact, live a perfect life. But I think that God's grace makes perfection a possibility.
I would say that I have opportunities to sin literally thousands of times a day. Every time I'm confronted with an opportunity to sin, there is a battle within my soul. The indwelling Holy Spirit is inclining me toward righteousness and obedience. But remember that the Holy Spirit is living in me, in R. C. Sproul; he's indwelling an imperfect creature, one who has not been totally cleansed of evil inclinations. So given the manifold opportunities to sin that I have and knowing that there's warfare with every one of those opportunities between what the Bible calls my flesh and the Spirit, statistically it's virtually inevitable that I'm going to sin and be far less than perfect. If we look at them one at a time, we realize that in each single circumstance the power has actually been provided by God to resist that temptation. That's why I can never stand before God and say, "God, you will have to excuse me; the devil made me do it" or, "The Holy Spirit was not powerful enough within me to have resisted that sin." So even though I believe that not even the apostle Paul ever achieved perfection in his life, it's not because of any lack of power or ability or inclination of the indwelling Spirit.