In the old days we signed letters laboriously by hand, writing, “Yours sincerely, ” or “Yours truly,” to those we knew and loved, “Love,”.  If you were truly formal, you might sign, “I remain, Sir, your faithful and obedient servant,”. Indeed, there is a whole wikipedia article about how people signed letters and notes: http://en.wikipedia.org/wiki/Valediction . 

Most people these days have some kind of sign off for e-mails, and even (occasionally) text messages. Amongst clergy and devout Christians you’ll see, “Shalom”, “Peace”, or “Yours in Christ,”. I’ve used a variety of these, but now I think I have found one I like.

“God be with you.” It’s simple, it’s a genuine wish, and it’s probably the case anyway. Also, it’s very traditional. Our phrase “Good bye” comes from it, at least according to the Oxford English Dictionary:  “Etymology:  A contraction of the phrase God be with you (or ye ); see god n. 8. The substitution of good- for God may have been due to association with such formulas of leave-taking as good day, good night, etc.” So I am really saying both “Good bye” and “God be with you.” I like that. So I am using it. 

God be with you!