History proves it has been. It also proves that they've fought each other too. Religion is a tool to spiritual enlightenment. Like any tool it can be abused or misused. All depends upon the user.
As you've pointed out, the complicity of pastors and priests in support of fascism and the brutalization of others is an example of the same coin.
OTOH, there are always people like
Pastor Martin Niemöller who wrote
this great piece of wisdom:
First they came for the socialists, and I did not speak out—because I was not a socialist.
Then they came for the trade unionists, and I did not speak out— because I was not a trade unionist.
Then they came for the Jews, and I did not speak out—because I was not a Jew.
Then they came for me—and there was no one left to speak for me.
Paster Martin Niemöller spent 7 years in prison, mostly in a concentration camp, under the Nazis. As long as the human race has such people, I think we stand a chance of surviving as a species.
FWIW, Niemöller was literally a U-boat Commander. Maybe that's where he grew his balls to stand against Hitler.