Religion is human self alienation
I’d use the word disidentification, but yes, at the core of most major world religions today is the goal of training the practitioner to turn away from selfish instincts. In Christianity, that is symbolized by nailing the self to a cross and letting it die.
How well that is understood and practiced by a majority of followers is another question.
Searching for answers to life's great mysteries is not self-alienation.
BUT believing in--and attempting to follow and obey--religious tenets calling on adherents to deny their basic human natures, calling them Satanic, IS very self-alienating.
No doubt about it.
Meaning what?
You need to support your assertion otherwise its just opinion. And to be honest, who cares about opinion if it doesn't have a supporting argument.