What on earth is friendship evangelism? If it means befriending someone so they will convert, seems unpleasantly sneaky to me.
Its what one does when one is with a friend or group of friends, and theoretically needn't have anything to do with religion, Floo. As you know, I'm involved wit Tools with a Mission. I often ask people whether they would be interested in getting involved in some way. I'm quite happy to ask someone whether they'd be interested in becomig a donor (perhaps of the parental toolkit that has been lying around unused in the shed for some years) with very little previous knowledge of the person. Asking whether they'd be interesting in being involved as a collector or a refurbisher/sorter tends to take me longer because I want to get to know where their interests lie.
But I don't see why that is anything other than asking others to get involved in a good cause, which of course people of all religions and none are doing all the time.
But if there is a back-door agenda additionally to suck them into your religion, well (as Floo puts it) that's a bit sneaky.
And actuality there is an issue here. Many people are quite rightly suspicious of 'hidden agendas' that exist all over the place and of course why a lot of people steer clear of getting involved in religious linked charities and activities. And thats for two reasons - first the one you talk of, the hidden agenda of conversion. But the other is simply that you don't wish to give an agenda you don't agree with (in this case religion, but it could just as well be a political party) the opportunity to promote itself through your endeavours.
So a good example in another context. Some years ago I was heavily involved in a non political campaign to save our local library. Although many of the leading people were actually members of a variety of political parties (Labour, Green, LibDem) we took the decision to make sure the campaign wasn't affiliated with any of them. Frustratingly the local LibDem councillors (who did bugger all) jumped on the bandwagon, and so the work we were doing was instantly seen as part of the plan to get a LibDem councillor re-elected (including all over their campaigning literature).
Very frustrating and why people can be wary of a hidden agenda.