So you can threaten to kill him and deny him his freedom of speech, however, you can believe whatever you want and say whatever you want? I'd also suggest reading up on the 10 Commandments, one of them seems to go along the lines of "thou shall not kill" or "thou shall not murder".
Agreed about this question too.
But... Is it only Christian who only use these commandments? How about other religion? Do they allow their brethren to kill people?