it literally means "losing my temper" or "going insane" to some degree. If you would look at the REM lyrics to the song by the same name, it makes more sense, it really has nothing to do with religion.
I was pretty much losing my religion after being forced to listen to rap music by all the freshman girls at my school.
radio modulation techique where information (usally voice or music) is added to the signal and changed by varying the freqeuncy of the transmitter. FM is the most commonly used modulation for radio signals techneque above 30 MHz.
the term "FM" is also used to refer to the broadcast band from 88.1 to 107.9 MHz, using that same modulation mode.
FM signals have less static because changes in frequency do not pick up interferance that AM-modulated signals do.