Mel Gibson caused much controversy around the time of this film's release, not just due to the on-screen content of the picture, but also due to his anti-Semitic rants.
His personal comments aside, The Passion Of The Christ is a brutally powerful piece of work. The final hours of the life of Jesus Christ are brought before our eyes with a stomach-churning, visceral conviction. All the spoken dialogue is in Latin & Aramaic, though there's not much dialogue going on, rather visual horror unfolding before our eyes with the events leading up to Christ's crucifixion.
Whether or not you're a religious person shouldn't matter too much, though it would probably be best to avoid the film at all costs if you're devoutly religious, it certainly isn't Sunday viewing to be paired with TV's Songs of Praise. Claims that it's a blasphemous depiction of events are a bit harsh, but it's certainly an unforgettable experience.