There is a group within the Catholic church that sees Reiki as occult. I forget their name, saw a website once. I doubt they speak for all Catholics.
I'll post a website reference for you over in Resources.
My view is, those opinions are out there, but the vast majority are interested and open. The same question comes up in other religions, as well. Generally I see that Reiki does no harm to anyone's faith.
Blessings,
Aronaya
