Just to comment to this interesting last bit of discussion going on here, where in the Bible does it say you should build a church with a steeple? Where in the Bible does it actually tell you how to organize or perform any church liturgy at all? In fact, there are very few instructions of any kind in how to perform any sort of ritual or practice, unless you go back to the OT where it gives details on how to do lots of rites and rituals. In the NT? No.
So "where does it say to do breathing exercises"? It doesn't. It doesn't say a lot of things that you do, and yet you do them because it brings you closer to God. Right? So why this question about meditation practices? To me, that is just someone's fear of the unknown and trying to brand or label it as "suspicious", and then hiding behind a "where's that in the Bible" question. The logic doesn't hold.
By their fruits you shall know them. No one has addressed, or can actually answer that in light of the claim, and evidence, of the fact that meditation practices (regardless of what form they take), do in fact make people more loving, compassionate, grounded in Spirit, bearing fruit in their lives, than they were able to prior to such practices. "An evil tree cannot bear good fruit". And to say mediation is opening yourself to the devil (that is ignorance), when the fact is people's live dramatically, drastically improve through such practices, is tantamount to the Pharisees, the ultra-righteous scripture believer's accusation of Jesus that he casts out demons by the devil. Jesus said in response, "A house divided against itself cannot stand".
Now as far as saying Christian mysticism is different than Eastern mysticism, that sound like propaganda. Eastern mysticism is not one thing. There are many forms and many practices and many techniques, from yoga, to emptying the mind, to chanting, to drumming to dancing, to pondering scriptures, etc. The point is, all of them take one into communion with the divine, and Christian mysticism does the same thing. And that to me, is all good.
It's not how you believe, or how you worship God, or what rite you perform, or how you meditated, but how you produce fruit that can only come through communion with God. By their fruits you shall know them, not by their practices. The Pharisees were concerned with such things, and Jesus said to them "You strain at gnats, while you swallow a camel".