I'm no Bible scholar, but I always understood "turn the other cheek" to mean doing so once, and not at the detriment of your life. I also have always understood that to voluntarily relinquish your life, when not advancing the Christian religion by martyrdom, was some sort of mortal sin. And that "rendering unto Caesar" did not go beyond precisely what was due into some sort of langinape.
Way back in the Olden Days us commoners were not permitted to stand our ground against our "betters" - those lords and knights and Saumari and such. But after 1776 there, at least theoretically, have been no "betters" in the USA. And Florida, last time I looked, was in the USA. There should never have been a concept of a duty to retreat, but since there will always be some weenies that want proof beyond all doubt (not just reasonable doubt) that deadly force was not employed only as the last resort, we got that "duty to retreat" stuff.
So far nobody has offered evidence that Zimmerman was not allegedly being allegedly beaten by Martin. At best there is a lot of noise about whether or not physical evidence of injuries to Zimmerman were discernable when viewing some videotapes taken over 30 minutes after the incident. (Did Zimmerman receive any medical care at the scene? Yes!) But presuming that the scenario offered by Zimmerman has some basis in fact, there is reason to allow a presumption that he could not retreat and that he had a reasonable apprehension of death or great bodily harm.
While I know it will never happen, I wish everybody would shut their traps and stop opining about an incident they have little, if any, factual information about. There is a Special Prosecutor assigned. The investigation is under way. Some sort of picture based on the evidence discovered should emerge within a reasonable amount of time. At that time the Special Prosecutor will either charge, present to a Grand Jury, or announce that there is insufficient evidence to charge.
What bothers me even more is that several individuals and groups are not only encouraging vigilante behavior but making public statements full of false information about where Zimmerman and/or his relatives reside. I just wonder if, should someone take action based on those exhortations and false information, if charges of contributory manslaughter be brought? I will not hold my breath.