This is an area where terminology gets real fuzzy. "Spiritual" is inherently vague and individualistic. I'm referring more to personal faith in a particular sect: read specific texts, pray in a particular way, organize your metaphysical model in line with an established religious tradition.

Generally I don't like to reference specific religious texts, my beliefs are much too syncretic for that, but I was raised Christian, and for all the faults of the various Christian institutions, Jesus himself seems pretty based:

And when you pray, do not be like the hypocrites, for they love to pray standing in the synagogues and on the street corners to be seen by others. Truly I tell you, they have received their reward in full.

But when you pray, go into your room, close the door and pray to your Father, who is unseen. Then your Father, who sees what is done in secret, will reward you.

If someone practices Christian dogma that way, I'd be hesitant to call them oppressed or an oppressor. It's still definitely a specific religion, but it's engagement with the emergent power structure that causes the oppression.