I read this article explaining fairly well why a Christian cannot practice yoga, no matter how much you try to detach it from the original context to make it just exercise.
Now, I am fully aware at least most of the members who believe in Christ probably understand what's the issue with yoga and its spiritual background why we ought not practice it in any form, but probably everyone knows a few people who cannot see anything wrong doing some yoga even though they go to church and read their bible every once in a while. So my idea was that this article could be handy in that sense.
I used to practice yoga for some seven years or so. Not any specific tradition of it, though and was doing it on my own, based on still rather old hand book and not any of the new age interpretation which of course does not really matter in the long run.
It is believed among the tradition of yoga that certain experienced are only due to lots of practice and discipline, but I found to get the 'kundalini' shoot through my spine and head rather effortlessly, the same with the astral travelling, and I sure did not stay hanging around the roof top but actually every time I separated my spirit body from the physical, I headed towards the space and saw some unspeakable things there. These are considered in yoga as skills that you develop as you open up more the spiritual. Well, needless to say, ever since after finding Jesus I've adopted quite a different perspective as for whatever spiritual experience I've had before, and with lots of repenting too.
I don't know if it was the seed of the mustard of faith that made it possible for these things to come about so easily, quite surely tagged by the devil to fool me around. The fallen one with his cohorts are always on the track if someone is sensitive for the spiritual realm in any way to be used not as an evangelist but a truth-twister.
Thank God, all of our experiences can and will be used to glorify the Father and the Son and the Holy Spirit, after we have received the Savior in our heart. By then, it really does not matter what you have been and where you come from, because Jesus Christ will lead you into a new destiny and many will follow if He's about your life.
Just wanted to share a small testimony here as well. The article was in some parts clarifying and will hopefully release many from the hold of the demonic caused by the yoga religion. Feel free to share.