I have been reading Francis Spufford's book "Unapologetic" (faber & faber, 2012) - sub-titled 'why, despite everything, Christianity can still make surprising emotional sense'. I went to hear him speak about the book recently at Cambridge's "Wordfest" book festival. Spufford says that he wrote the book because he couldn't find that anyone else had covered the ground. There is plenty of deep Christian apologetic, but it is not so easy to find someone taking a more ordinary approach towards justifying holding a Christian faith. He pointed out that it is simply not fashionable in our society and culture to be a Christian today. Indeed, many so regard it as weird that it can be embarrassing to admit to a Christian faith. However, he would want to contend that Christianity has much to say to today's world, and indeed makes sense of it.
Spufford adopts a very realistic approach and believes that Christianity does so as well. For instance, Christian faith recognises that we get it wrong - and we just need to get on with accepting that. He writes - p. 169 - "If Christianity is anything, it's a refusal to see human behaviour as ruled by the balance sheet. We're not supposed to see the things we do as adding up into piles of good and evil we can subtract from each according to some kind of calculus to tell us how, on balance, we're doing. Experience is not convertible. Cruelty cannot be cancelled by equal and opposite amounts of being nice. The weight of sorrow is not lightened by happiness elsewhere. The bad stuff cannot be averaged. It can only be confessed."
Of course, it's true that Jesus told us to be perfect - but he accepts that we won't be!