Well, how I’ve always understood it is as a general prayer. It’s like when someone says to pray for an end to abortion or for the safety of all travelers. You don’t know all the people travelling or all the people that are contemplating abortions and the doctors willing to provide them, but you do pray for those people. I think it’s just Christian goodwill.
I’m sure there is an actual already-made-up prayer for the sick, but I do not know of it. If you find one, post it here or post the link. ” title=”Smile” />