This is a difficult question. It is commonly reported that religious intervention by priests makes poltergeists react angrily,and blessings do not dispel them.
I have read accounts by priests experienced in dealing with the paranormal who comment that their intervention would make a poltergeist worse... although I can't remember my sources (I've read too much, sorry!)
I am a practicing Christian, and yet I experience sporadic paranormal phenomena. I even encountered an angry ghost in a church some years back.
When I had a particularly nasty sleep paralysis event, which really felt like something was trying to claw its way through my brain and take control of me, prayer caused the attacker to rapidly retreat and attack someone else (I awoke and my wife started to struggle and scream in her sleep, I woke her up, and then I heard my neighbour starting to scream in her sleep). So it seems to me that faith and prayer have power, but not against poltergeists.
Relevant here is a translation I did of a Mexican poltergeist case:
https://forums.forteana.org/index.php?threads/ghosts-poltergeists-obscure-cases.67403/post-2050393