Justin Bieber joined a group of friends on the beach in LA yesterday. He went shirtless and showed off his muscles by doing push-ups in the sand with his pals. Justin wasn't just displaying his abs — he also debuted a tattoo of Jesus on the back of his leg. He had the new ink bandaged up during a December getaway with Selena Gomez in Cabo, where the couple shared PDA poolside. They were together again for NYE in NYC, but she didn't join Justin for his latest outing. He had the company of his dad, Jeremy, though, earlier yesterday for an a.m. visit to the gym.