The Protestant Pastors Emergency League (PEL), opposed the pro-Nazi Reich church for two reasons:
trying to force regional churches into one national state controlled church
b. Nazi attempts to prevent Jews being Christians and banning Jewish Old Testament teachings.
In 1934, the PEL set up the Confessing Church, to rival the Reich Church.
About 6,000 pastors eventually joined the Confessing church while 2,000 remained in the pro-Nazi Reich church.
About 800 pastors were sent to concentration camps for criticizing Nazi policies.
After the breakdown of the Concordat, some Catholic priests also criticized the Nazis.
400 Catholic priests were sent to Dachau concentration camp.
There was criticism by Bishop Galen in 1939 of the T4 programme to murder physically and mentally handicapped children.
The most famous religious opponent of the Nazi regime was Pastor Martin Niemoller. He was arrested by the Gestapo and sent to Sachsenhausen camp in 1938.