Dear Jeremyp and ProfDavey,
The hole that needs filling, where do we start, what about this country and then we might look further afield.
Church of England, how would you fill that hole? And before anyone answers, please think very carefully about what that encompasses, you can start at the top and work your way down ( Her Majesty ).
There are plenty of people, including I gather a majority of Christians, who support disestablishment. So I don't see why this would be a problem at all - indeed it would solve a major anomaly in our equalities view of freedom of religion, in that it would allow the head of state to be of whatever religion (or of no religion) aligned with their own conscience.
The Sally Ann, how do you fill that hole?
Barnado's, how do you fill that hole, and please remember that our own government uses that charity for help and advice, actually when I think about it, this country would be in a very poor state if we didn't have the likes of the CoE, CoS, Sally Ann, Barnado's.
For every religious charity there are many more non religious ones working in the same area. Indeed the major charities in pretty well every charitable area (except religion itself) are non religious. You do understand that something like 90% of all charities in the UK are non-religious. So there isn't really a big hole to fill is there.
And on voluntary work - studies have indicated that non religious people are just as likely to be involved in formal and informal volunteering as religious people. Also charitable giving outside of direct contributions to a church are the same or greater from the non religious population than the religious population.
Remembrance day, how do you fill that hole?
Remembrance day started and has always been fundamentally a non religious commemoration, albeit religions have muscled in. You will note that the cenotaph, the site of our main remembrance event, is not in the shape of a cross and I gather was deliberately designed to avoid any overt religious symbolism to align with the primary non religious origins of the commemoration. So no hole to fill there either.
Easter and Christmas, okay granted, commercialism is doing a very nice job of filling in that hole 
Well actually for many people the prime focus of Christmas is neither religious nor commercial, but to mark mid winter and to share time with those closest to us, our family and close friends.
And, of course, both festivals have origins in paganism that pre-date the Christian festivals (in one case they never even bothered to change its name from that associated with a pagan goddess).
http://www.bbc.co.uk/news/magazine-25465210
Is it your hope that one day all the above in the link will just be tourist attractions.
No hole here either, as effectively virtually all the examples are already fundamentally tourist attractions and markers of our cultural heritage. There is very little actual religious worship going on at most of them - and the numbers of worshipers is tiny compared to the numbers of tourists or visitors interested in the cultural history.
Then we need to consider our kids education, and no I am not talking about the three R's, morality, ethics, compassion, these are far more important than the three R's, and please don't say these are subjects that should be taught at home, in this disjointed country of one parent families or Mom and Dad out working all hours.
We need schools to be molding our kids to be fine up standing citizens, Love Thy Neighbour should be tattooed onto their foreheads, ( figuratively speaking ) I don't see any push in education for this, what I do see is a race to the bottom, how do we make educating our kids cheaper or the X factor I am all right society.
Sure the moral and ethical future of society is important, but whether this is better or worse than decades ago is debatable - certainly the young people I know are pretty well hard-wired against racism, sexism homophobia etc in a way that was unthinkable when I was a teenager when casual (and not so casual) racism, sexism and homophobia was rife.
But I don't see what this has to do with religion - you do understand that religion doesn't have a monopoly on ethics, and that non religious society including our non faith schools are as committed to developing 'fine up standing citizens' as religions and faith schools. So no hole here either.
Gentlemen, you have a massive hole to fill and I have never ever heard any constructive comments on how you go about this on this forum.
Gonnagle.
Nope every one nailed - no holes to fill.
Actually if I am honest were religion to vanish overnight, there would, of course, be a significant realignment in society simply because religion currently does exist and is important to a small minority of people in the UK. But this isn't really what I am talking about - rather I am talking about a continuation of the decline in religiosity in the UK that we have seen over the past 50 years or so. The rate of that decline means that society constantly adapts to a dwindling in the numbers of people who are actively religious and see religion as important. So society is well able to gently fill in the 'holes', as you wish to call them, as fewer people see religion as important.
