Do you have a citation? It says he was an ordained minister to marry his brother, but no specific religion was mentioned.
Well, he has attended a Christian Church and he also married Valerie Bertinelli to her new husband. I didn’t read that he became an ordained minister just to marry his brother. I’m assuming the best I guess based on what I have seen online:
https://www.vhnd.com/2012/03/11/eddie-and-alex-van-halen-attend-church-in-studio-city-nj/