////I recently heard 'Amen' described as 'the biblical equivalent of "Send"'.////

So is it "send" or "so be it"? See what I mean? They disguise the source of the word. Amen is the Hidden God that you pray to in private and never tell anyone what the prayer was for. This has roots in magic and such going back centuries. In hoodoo, for example, one buries an object in the casting of a spell and nmust never tell anyone where. The spell being what? A desire for a certain outcome. In short, a prayer.

I was reading this book on sex magic and it mentioned that after practicing a sex magic ritual, if one has a desire of some sort, reduce it to a symbol and draw that symbol on a piece of paper. And then never look at it again. The symbol shold be fairly complex because you want to forget what it looked like. You never tell anyone about it. It must be secret. Now, I'm not saying this works or doesn't work, I wouldn't know, but it demonstrates that when we pray, we pray to the Hidden God and that prayer is a secret. In this sense, group prayer for a specific outcome might have been seen ancient Christians or magic practitioners as totally useless because prayer must be individual and it must be known only to that individual to be effective.