Elisabeth111,
Following a different religion is like learning a foreign language. It is obviously a more difficult process to understand concepts. But sometimes, learning foreign languages is fun. Scientists say that multi-lingual people are usually more articulate in their own language. And it is not uncommon to find people penning brilliant prose or verse in languages not native to them.
I don’t think anybody should be kidding themselves that Yoga is not a religion. It is a complete system by itself ! It needs no other religious or mythological imagery to get to the end. And it is only “one” of the many many religions that exist in the fold of the so-called “Hinduism”.
But Yoga doesn’t demand absolute loyalty from its followers. It even encourages people to try out other religions. In this way, Yoga can be thought of as “compatible” with people actively following other religions. I think you can easily follow Yoga and believe in Jesus, and offer your prayers in church. Actually, Yoga is more about doing than about believing. Believing hardly gets you anywhere, even in Christianity.
Think about it. If you are learning a foreign language, you expect the teacher to speak in that language in the classroom. So obviously, Yoga classes would be based on the culture where Yoga was developed - ancient India. But I agree some Gurus can be better than others. It all depends on your luck as a student to find a good Guru