One of the most fascinating passages in all of Paul's writings is his monologue in Romans 7 concerning his own struggle to live the Christian life. Here is part of it...
I realize that I don't have what it takes. I can will it, but I can't do it. I decide to do good, but I don't really do it; I decide not to do bad, but then I do it anyway. My decisions, such as they are, don't result in actions. Something has gone wrong deep within me and gets the better of me every time. It happens so regularly that it's predictable. The moment I decide to do good, sin is there to trip me up. I truly delight in God's commands, but it's pretty obvious that not all of me joins in that delight. Parts of me covertly rebel, and just when I least expect it, they take charge. I've tried everything and nothing helps. I'm at the end of my rope. Is there no one who can do anything for me? Isn't that the real question? The answer, thank God, is that Jesus Christ can and does. He acted to set things right in this life of contradictions where I want to serve God with all my heart and mind, but am pulled by the influence of sin to do something totally different. (Romans 7:18-25 THE MESSAGE)
Living the Christian life often feels like a tightrope act. It's such a challenge to walk in the Spirit, and then watch as my flesh acts out. It's frustrating! But what Paul describes as his problem is in fact a problem for all of us. How do we live a life that pleases God? What Paul, and millions after him, discovered is that we cannot do it. You read that correctly. We cannot do it. Only Jesus Christ living his life in and through us can do it. He is the only one who can live the Christian life....so as I find myself on the tightrope of living a godly life in a fallen body I must allow him to live his life through me. He is the one who can keep me from falling.