My personal belief is that freedom of religious expression should be protected by the law, but religions themselves should get no special status. So a charity that happens to be run by a church would be fine as long as it followed all the rules for charities (such as not just being a means to recruit for that church, just like I don't think a charity should just be the means to recruit for a gaming club), but a church itself would receive no special tax status beyond any other not-for-profit.