spiralbound you said What do you see as the main prerequisite for going to your church OP - being a believer or 'seeking', or being a member of the community, who may not 'seek' for years if ever and who may never tell you they are seeking, or even that they have come to believe?
There is no prerequisite for going to the church I go to, other than the desire to go there.
Could I tolerate the idea that some people at my church may actually be agnostics? Of course. But in reality I would be surprised that anyone would give up a couple of hours on a Sunday to be with people who believe something they do not believe simply because they feel aligned with and influenced by the ethics of Christianity. I know some go because they support husbands or wives who go and they themselves are not Christians, not in my current church but in previous ones. And some kids may still go but not want to yet are too young yet to be left at home.
I guess most who go have some vested interest in the spiritual side. I have never met anyone drawn by the 'ethics' of the Christian faith alone.
Yes, I can imagine some inspired or comforted by the rituals of going to church. Maybe some who never believed but grew up in the church or some who came searching, never found, but stayed. But in reality mine is what is called a low or evangelical Anglican, which means few candles, no statues and no incense, so ritual is minimal. The vicar waves his arms around a bit sometimes but aside from that, little ritual. 
I don't exactly want lots of declarations of belief outside of services or to be able to chat socially about how great Jesus is with everyone? I would like people to find faith in Jesus for themselves, however they find it. The church's aim is to facilitate this, not to force it. As I see it.
Maybe churches have always been places where people want to talk to you about Jesus - he is the main guy! But I think in the past people had reasons to go, social reasons maybe, but now there are few social reasons to go aside from wanting to follow the faith (excepting maybe with some churches and some schools but do not want to get into that).
In any church people are free to keep themselves to themselves, we don't pounce on people and ask them what the Lord has done for them lately but I am sure there are churches like that. I must say I go to a C of E church and at it's most hand-raisingly-happy-clappy the C of E still allows people to take a step back, be quiet, not join in, not shout about it. And if one does end up in a hand-raisingly-happy-clappy C of E (as I was about 5 or 6 years ago) there will always be another C of E nearby that is very different. So one never really gets forced to be a certain way in this country. It may be different overseas or in a very rural setting.
spiralbound Please could I ask, ...what puts people off, what do you mean by evangelism puts people off? Please do explain because it would be good to know what people mean. Would a leaflet through the door put you off? A knock at the door to sat we are local and you are welcome? An invite to a free meal or picnic? An invite to a fair? Either in person or by flyer?
What would put people off as well as on, is a good question.