A pastor helping asylum seekers in Frankfurt said some Muslims who have arrived there have a resentment towards Christians and see them as being "unclean".
Pastor Mahin Mousapour warned that many believers were scared into hiding their Christian faith.
"Many Muslim refugees say that all Christians are unclean," she told the Daily Express.
"The victims are afraid of revenge or of losing their asylum status if they complain.
"It cannot be that someone seeks shelter with us because of his faith and we then don't protect him here."
She said Christians were forced to fast during the Muslim festival of Ramadan because camps changed meal times.
They are also being forced to make excuses to attend church, she said: "When they come to us to church on Sundays, they often pretend to be visiting friends."