You can find English subtitle files (typically in .srt format) for this movie on several reputable platforms:
Gibson deliberately used dead languages to create a sense of timelessness and authenticity. Without subtitles, the emotional weight of the dialogue—specifically the debates between Caiaphas and the Sanhedrin, or the haunting whispers of Satan—is lost.
Mel Gibson’s The Passion of the Christ (2004) is a unique cinematic experience. Unlike almost any major Hollywood release, the dialogue is not in English. It is spoken entirely in reconstructed Aramaic, Latin, and Hebrew.