The Sign of the Cross (1932)

This 1932 film by Cecil B. DeMille, which you've probably never heard of (let alone seen), may be one of the most entertaining Christian movies to come out of Hollywood, even though it includes some things that might raise some Christian eyebrows (e.g., barely-hidden nudity, gratuitous violence and gruesome scenes, etc.). From the synopsis at The Internet Movie Database:

After burning Rome, Emperor Nero decides to blame the Christians, and issues the edict that they are all to be caught and sent to the arena. Two old Christians are caught, and about to be hauled off, when Marcus, the highest military official in Rome, comes upon them. When he sees their stepdaughter Mercia, he instantly falls in love with her and frees them. Marcus pursues Mercia, which gets him into trouble with Emperor (for being easy on Christians) and with the Empress, who loves him and is jealous.

Look for a young John Carradine at 1:53:34 as one of the Christians being led into the arena to be devoured by lions.

It's been nicely restored on DVD by Universal Studios to its original length, including all the "sinful" and gruesome scenes that were cut by the Hays Code. It's available through Netflix.