"Keep watching and praying that you may not enter into temptation; the spirit is willing, but the flesh is weak.”
IMO, self mastery makes no sense unless one realizes that he is both a soul and a body and that the inclinations of the body aren't very noble. So...you basically would have to think that there is a goal beyond self preservation and physical enjoyment - the animal inclinations. This isn't to say that there isn't a time and place for such activity, but the noble activity supersedes all side missions.
Of course this concept of the noble mission, the noble endeavor, or even attainment of enlightenment, makes no sense to the modern "christian", as his religion amounts to chanting "Jesus died for my sins" and then do whatev, but to the more serious student it can't be overlooked.