This is not a judgement, just an important lesson. On some level you are seeking their approval. Find approval within self and from GOD and the Masters. You know what you are saying is true, why let fundamentalist Christians shake that belief. You must fully own your power and be completely clear and confident in your beliefs.
All spiritual teachers get flak.
Look what Jesus went through. Even Sai Baba is attacked and he is a Universal Avatar. It is happening to make you strong. You must let it slide off like water off a duck's back. If you are very clear in your beliefs and convictions what other people say will not matter.