Remember how the difference between 'Yours sincerely' and 'Yours faithfully' was drilled into you at school? The trouble is that emails and social media mean that conventions like that look as dated as 'Your obedient servant'.
But fear not. Christians, always eager to bless the world, have been relentlessly creative in developing new sign-offs which are both fit for the digital age and spiritual too. And not a bit cheesy.
Christian Today has identified 10 of the best.
In His Grip
There's something pleasingly manly about this, smacking of a firm handshake. Or it might put you in mind of Bear Grylls holding someone by the collar as they dangle over a precipice. Either way, it's sort of comforting.
Be the Light
An earnest exhortation, this one, and biblical too. The trouble with all exhortations is that sometimes you don't feel like being exhorted. That might be the exhortee's problem rather than the exhorter, of course.
Saved to serve
There's a certain theological difficulty with this one, in that it's wrong. We are just saved, and service is a free response to God's grace. Being guilted out by an email sign-off is something we don't need.
Under Aslan's Paw
The potential for mystification here is huge, particularly if it's in an email sent to, say, a gas company. And though of course many Christians would get the Narnia reference, isn't it just a bit, well, odd?
Under the Lamb
This one conjures up an image of a tragic accident in a supermarket meat section. Never, ever use it.
Covered in the Blood
A sign-off that might appeal to fans of Dexter, the hit series about the serial killer with a heart of gold, but not to most normal people. It's sort of biblical, but gross as well. Explain it in a sermon, don't tack it on to an email.
Only by Grace
This is one that seems to cry out for the rest of the sentence, and we don't know what it is. Only by grace what? There's a song that begins that way, but can OBG users be sure everyone knows it?
Watching God Work
How about rolling up your sleeves and joining in? There's quite a bit to do.
Soli Deo Gloria
Translation: 'Pretentious, moi?' Actually, it means 'To God alone be glory', but if you say it in Latin people think, 'Wow! He knows Latin!'
Jesus Loves You!
Impossible to argue with but at the same time irritating. It's the exclamation mark. Imagine it: "What time's the meeting tonight? Jesus loves you!" And what happens if you have to get theological on someone? "You're a heretic and you're going to hell forever. Jesus loves you!" No.
Follow him on Twitter @RevMarkWoods