To me this is a similar question to eating food offered to idols.
See 1Cor 8, 10.
1 Corinthians 8:7 (NIV)
Some people are still so accustomed to idols that when they eat such food they think of it as having been sacrificed to an idol, and since their conscience is weak, it is defiled.
Admittedly I don't know much about Hinduism or yoga, or any relationship between the two.
I would never know one was related to the other unless someone told me.
I would never know that some perceive it to have demonic connections unless someone told me.
I would never suspect certain stretch poses are perceived by some as worshiping demons.
In fact, this is the first time the notion had even crossed my mind. I feel tainted now.
Frankly, I'm surprised that in this day and age, the connection is even made.
So I would conclude if your church, or those whom you associate with thinks is not good, then don't do it.
On the other hand, if nobody's conscience is in any strained, if the Spirit is not compelling you away from it, if no one is aware of an issue, why create one? People can, and do create issues out of everything, and come up with rules about what you can and can't do. Don't listen to this music, don't read this book, don't do that dance, don't wear that color because there is some demonic connection. But is there really? If we start trying to protect ourselves from things that aren't even true, we give faith to that false belief. If we tell others not to do something because they worship other gods, implies there are other gods. But there is one God. If I can't do some stretch or pose or whatever they do, because I'd be worshiping some false god that doesn't exist, whether I realize it or not. Now I can't do it. Christ freed us from such notions, didn't he?
Galatians 5:1 (NIV) 1 It is for freedom that Christ has set us free. Stand firm, then, and do not let yourselves be burdened again by a yoke of slavery.
