Blasphemy (Blasphemy the Movie) (2001)

Martian Garcia announces to his parents that not only is he proud to have converted to Atheism, but he intends to tell his whole family on Christmas. His parents then disown him on the spot, and they turn to his Aunt Patrica, who turns the rest of his family against him, and she's determined to either bring him back to the fold or kill him trying.