The concept of the leap of faith is pretty central to the view of religion which most people hold in western culture today. It can be given a positive or a negative spin. Negatively, the leap of faith is portrayed as ignoring the facts, running contrary to the evidence, 'committing intellectual suicide', throwing oneself into the darkness even though the light of knowledge is shining all around. On this view, a leap of faith means plunging into absurd mysticism, usually because one is unwilling to deal with the cold, hard facts of life. Positively, the leap of faith is portrayed as reaching out for something 'beyond', something that transcends the mundane, something that provides meaning and purpose in a universe otherwise devoid of both. Although the leap does take us beyond knowledge, per se, it is somehow a virtue to trust in something - almost anything - that will give our lives a bit of content - and who knows, maybe that something is really out there.
Christians tend to divide into those who hate the idea of a leap of faith and see no place for it in Christianity, and those who embrace it. Broadly speaking, the former believe that Christianity is based on evidence and rationality, can be demonstrated, and does not involve any leaping because it is all within the bounds of what is ordinarily referred to as knowledge. They tend to be keen on the discipline of apologetics, and to have some regard for natural theology. The latter, on the other hand, do not believe that the arguments and evidences will get you all the way. They may vary as to how far they will get you - perhaps very close - but at the end of the day, you will have to make a leap. You will reach the end of your intellectual resources, and the arguments and evidences will take you to a point from which you just have to jump. If God is there, presumably he'll catch you.
I would suggest, of course, that neither of these positions is quite right, mainly because they both have something desperately wrong in common. Both believe that human beings can work it out, sort it out, and live it out, without assistance. Either we have to think it through, or we have to jump. Either way, the decisive action is ours, and comes on our side.
What if revelation were needed - personal revelation, God stooping down to meet me? What if instead of the leap of faith we were presented with the 'leap of grace'? What if it was all, in the end, about receiving?
"If we know ourselves, as the Christian does, we cannot think that we are capable of this leap. And the whole idea of a leap that we have made or are making is best abandoned. No one makes the leap. As Christians, we are all borne on eagles' wings."