I too am a christian and have been doing research into chi for a while now. There has been a lot thrown into the discussion to think about. Whether or not chi is a spiritual force or can be explained in terms of physics, I still haven't made my mind up - at the moment I think it may be a bit of both. As for whether Christians should be involved in using chi/ki, the more I think about it the more I'm convinced it depends on your starting point and also the attitude with which we individually approach it. For intance, I have no problem with the chi existing and doing what it does, but the function and place it has is assigned by God.