When talking about how we ourselves are involved in spiritual growth, the biggest mistakes have to do with mixing up what job belongs to whom. We either take on far too much of the task and attempt spiritual growth by direct self-effort, or we become too passive by praying a short prayer for change and then waiting for God to take over our life. In fact, we might best define discipleship as the art of participating with the Master. Learning how to follow is as important as attempting to follow at all. To paraphrase Paul:
"If anyone has reason to have confidence in their own abilities, it's me! I have accomplished more in my life than most people ever dream of doing. But all my efforts to become holy were actually worthless, especially when compared to what has happened to me as I got to know Christ personally and to have Him pour His righteousness into me. Not that the job is done or that there is nothing for me to do in that process. In fact I continue to move forward as I appropriate more and more of that which He rescued me for." (Phil.3)
Here we get a glimpse of this balance between God's part and our part. Initially, Paul (Saul) made the mistake that most people still make today — He tried as hard as he could to become what God wants us to be. There is a kind of logic to this, of course, since nearly everything else on this planet has to be earned. But that is what makes the spiritual life so different. Jesus said that when it came to kingdom life, there were a lot of things we could not do by direct effort. It would be like trying to grow a foot taller by sheer willpower. No, growth is a very indirect process in which we are intimately involved. As a child, if we eat right and exercise, growth will happen. But if we try to subsist on potato chips and play around toxic waste dumps, we will probably die before we get any taller. We are involved in important ways, but only to make a space for God's design to produce the growth we need.
We see the same thing in Jesus' metaphor of the Vine and branches. The only way for a branch to produce fruit is to connect well with the vine. But in most of my early Christian training, we all took course after course on how to manufacture grapes by direct effort. That's mixing up my part and God's part, in the worst way.
The single most important task in being a disciple is not learning how to serve or how to interpret the Bible or all about the basic doctrines. Our first and most important task is to learn how to be a disciple! Otherwise, no matter what effort we put forth, we will end up becoming something else.