Thanks to some divine intervention ... we've learned Bieber's friends are Laura and Ava Lentz -- wife and daughter of his pastor and pal Carl Lentz.

Nothing to see here, folks.

Justin Bieber's a fan of three's company ... it's how he rolls.

The Biebs was hanging onto a brunette beauty while walking near the shore in the South of France. The younger girl appears to be tagging along -- maybe the daughter of Justin's companion? Whatever ... he doesn't seem to mind.

Justin's girl has great taste -- not because she's with him. Check out her Kate Moss tank.