Will Ferrell and Steve Carell have signed on to star in Swear to God, with actor-screenwriter Justin Theroux locked in to make his directorial debut for Warner Bros.

The comedy centers on Will Ferrell's character, an arrogant hedge fund manager whose life is turned upside down when he is convinced that he actually saw God. No details were given for Steve Carell's character.

Justin Theroux will direct and rewrite the screenplay originally written by Due Date scribes Alan R. Cohen and Alan Freedland. Will Ferrell will also produce alongside his Gary Sanchez Productions partners Adam McKay and Chris Henchy.

Production is scheduled to begin next July, after Will Ferrell wraps on Anchorman: The Legend Continues. Justin Theroux previously wrote the screenplays for Tropic Thunder and Iron Man 2.