Every Christian must eventually grapple with the issue of sanctification, that is how to become more like God, and sin less. When someone is radically converted, this is often a non issue for a while. It seems like God just removes so many things from their old life so quickly that sanctification is an automatic process. However, as Christians grow, they often hit a point where it is not as easy as it once was and they start to wonder what happened.
There are many different ways that Christians throughout the ages have addressed the problem. On the one hand, people might tell you that you do not need to do anything because God’s “grace” covers all of your sin. This passive view of sanctification relieves stress but at the same time it can quickly become an excuse for sin. God will clean you up when He is ready. Let me tell you that God is against sin, and he is always ready to clean you up. We have an important part in the sanctification process.
On the other hand, people might tell you that in order to be acceptable to God you must do a variety of things. For some this is a set of outward strictures like how you dress, for others it is a level of inward purity that you must perform. If you do not do these things, then it is not really clear if you are saved or accepted by God. Now of course, rarely would anyone teach something so openly counter to the Biblical truth of salvation by faith, so often, these requirements are presented in a subtle way such as through psychological pressure. Any system that creates fear about your salvation over something you do, or do not do, will lead to legalism. Whenever you feel that you must do something before you come to God to repent, you are in what many people call legalism, that is a focus on outward issues in stead of the inward issues of the heart. This is what Jesus castigated the Pharisees for when he said they “clean the outside of the cup and the dish, but on the inside you are full of greed and evil.” Focusing on fixing the outside will actually make you worse!
The solution is not to try and fix yourself, or to ignore your sin. The solution is bring your sin before God and allow his love and forgiveness to minister to you. If you are insecure in your relationship with God, or feel unforgiven, or that you must do an endless list of things to be right with Him, you will stay “in works” rather than in faith or grace. It is actually the love and presence of God that changes us. Feeling unforgiven, insecurity, or likewise, cuts off the flow of love from God, and stops us from any real inward transformation. As long as we feel these things we are guaranteed to be “in works” or legalism as we try to fix ourselves.
Another way to produce legalism is to emphasize “instantaneous sanctification.” This doctrine tells people that they must be sanctified at a particular moment in time and after that, they should never sin again. Of course, they do sin again, and when they do, they work hard to keep “sanctified.” Forgiveness or “justification” is immediate, sanctification is a process. It is an active process of turning from our outward sin and trusting God to cover the hidden sin of the heart.
This leads some people to resolve the sanctification issue by saying that you cannot lose your salvation. As long as you know you had it (many people do not), then this seems to be a way to be secure. The problem is that when you read the Scriptures, for example in Hebrews, they seem to make very clear that you can lose your salvation, encouraging us not to. Moreover, human experience shows us that some who truly believe ultimately walk away from God. I believe this is easily resolved when we realize that salvation is not conditioned on our perfection, or even near-perfection. It is based on our receipt of His Love and acceptance of His authority over our lives. If we walk away from Him, or we throw off the standard of his Word from our lives, we should fear our salvation. When someone says I am a Christian and I think it is OK to sleep around with lots of people, they should fear. The one whose heart is directed toward God and desires to follow his commands by His grace should never fear, however.
This issue has been wrestled with through out the ages. In fact Martin Luther himself had to deal with it extensively as part of starting the Reformation. He had to come to realize that by focusing on every little “sin” that he committed, he was, like the Pharisees, straining out a gnat instead of dealing with the much larger issues of sin in his heart. One of his great works in dealing with this subject was his Commentary on Galatians. This was the book that they were reading when John Wesley, who had struggled for at least 10 years with his salvation found his heart “strangely warmed” and from then on knew that God had saved him.
I personally wrestled with this for almost 2 years while I listened to a very fear inspiring teacher, and attended a church that promoted certain works oriented doctrines. I constantly had Scriptures playing in my head accusing me and scaring me. I felt that at any point I might do something horrible to someone or myself and thereby lose my salvation. The only reason I felt that I might do something like this, though, was because I was in such tremendous fear! I felt as if I were teetering on the edge of hell itself. Finally God used the life’s work of Puritan Walter Marshall to being to remove the bondage from my life. His work, “The Gospel Mystery of Sanctification,” although hard reading, perhaps gives the ultimate antidote to someone who has developed a hard core bondage of legalism. Using a mountain of Scripture, and working through every nuance that the devil could throw at you, he shows conclusively that it is only by trusting in God that we have any hope to be purified from sin. We have an abridged version available for download.
Women in Western culture very frequently struggle with works, but in a much different way than men do. Whereas men who struggle with works seem to wrestle with exactly how to deal with their sin and with finding the correct theology, I have found that in the lives of women that I have known that works comes in a very different way — trying to be perfect all of the time, either to an outward or an inward standard. If they are perfect, then they will be approved by others, and if they are not they will be disapproved. 
This carries over into their relationship with God, where they try to relate to Him by dotting all of the i’s and crossing all of the t’s. This method of relating to God does not work, and makes living a life for God a continual struggle. My wife has had some success breaking this by listening to Jim Richards’ tape series on “Faith Righteousness” Richard’s work in general is a very good on this topic. In fact, for an introductory level, his book is the best of all: Grace: The Power to Change.
If you are not from a charismatic or pentecostal background, the idea of things like tongues, prophecy and divine healing may be difficult to wrestle with. On the one hand, you may be attracted to the more relaxed atmosphere at a “Spirit Filled” church but is someone about to bring some snakes out? Or possibly you may have been taught that the miraculous gifts of 1 Corinthians 12 ceased with the apostles and the completion of the canon. These are perfectly legitimate issues to wrestle with. Former Dallas Theological Seminary professor Jack Deere wrestled with these issues in a serious way and wrote two very penetrating books about the subject: Surprised by the Power of the Spirit and Surprised by the Voice of God. If you are dealing with the Biblical data on this subject especially, or come from a Christian home where the gifts were not emphasized, these may be helpful for you.