Having posted a few questions (on organic church), read some Todd Hunter, Willard and chatted over coffee with a few people on the issue of commitment I've finally come to some conclusions. I had been thrown off by a comment that was made by a much respected leader when I probed him on the issue of spiritual disciplines, that they are "not required to merely be in the family." I interpretted this to mean that the desire for deeper walk with God (and "training" for that Goal) is not required for you to be in the family. From this I started to ask more questions: how will we change our communities if we don't need to change inwardly? and eventually came to the question of whether there are different levels of commitment to Jesus within the category of "follower."
This discussion isn't so much to do with different stages on the same course, it's more about whether there is a stage at which you can comfortably stop growing and still be a follower of Jesus. My conclusion is that being a follower and growing are very closely linked.
For me the issue led to the question of what are essentials and what are non-essentials. In Ephesians Paul corrects the Gentile followers who have been confused by the Jews saying that "you must be circumcised" in order to be a true follower. In other words they were saying "Jesus + Circumcision = Salvation" and Paul was saying: "no you've got it wrong - it's only by Jesus that you have salvation (i.e. Jesus = Salvation). Now I could go into a discussion of 'what is salvation' but that would be a digression from the point I'm trying to make.
Basically there are things which fit in the same category as "circumcision" in the above equation (for example "not drinking" or "spiritual disciplines"). Then there are the essentials...I've decided that "spiritual formation" is one of those essentials which should be part of any definition of a follower of Jesus (AKA Christian). On the other hand the non-essentials have no 'value' in themselves, but may be in the form of tools that can be used to attain spiritual formation.
NB. I'm not suggesting that circumcision is a tool for spiritual formation!