Are the twelve spiritual disciplines biblically sound?

I was reading about Renovaré and came across the "twelve spiritual disciplines": meditation, prayer, fasting, study, simplicity, solitude, submission, service, confession, worship, guidance, and celebration My first thought is that the list almost sounds contrived (being exactly 12). However, when I look at each one, I can see how each of these things *might* be able to help us grow spiritually. Is this list found in the Bible somewhere or was a contrived list? Is this the only twelve items that can help you grow (or even the "top twelve")? Are there any one of the twelve items that may be contentious or can they all truly be ways to grow in faith? [More info at their website](http://www.renovare.us/SPIRITUALRENEWAL/PracticingLikeJesus/WhyPracticeLikeJesus/tabid/2518/Default.aspx)