What will happen if I seal a crack in the wall that has mold growing behind it?

Just moved into a rental home a month ago that we started to notice had a leak coming from the shower. Apparently some of the caulk had separated from the shower walls and water leaks down through the floorboards/wall to the garage below. There is mold in the cracks and under a ledge (which is where I think most of the damage/leaking is coming from). There is obvious water damage on the ceiling of the garage and I have a feeling that someone's tried fixing this problem before because there is an area that looks like it had been cut out before. If we clean out the cracks in the shower and re-caulk it, will mold continue to grow behind the walls?