Because the god of conservatives and the GOP wants them to kill brown teenagers – from the Sean Hannity interview:
Despite the apology, Zimmerman made it clear that he didn’t regret any of his actions, because it was all divinely pre-ordained. “It was all God’s plan, and for me to second guess it or judge it…,” he said before trailing off. When Hannity asked if there was anything he’d do differently in retrospect, Zimmerman answered, “No, sir.” Later he added, “I do wish there was something, anything, I could have done that wouldn’t have put me in the position where I had to take his life.” Earlier in the interview, Zimmerman defended having a gun on him, noting that he always carried one unless he was at work.
When people walk around with guns, they will use them. God + guns = dead people. It’s that simple.