I recently was reading about one person's faith journey from Christianity to Atheism and then back to Christianity. Jim Thring, the person in question, describing how the emotional side of his faith started drying up and he began to question Christianity, eventually coming to an atheistic position. But later he notes, "But then I found myself starting to question the narrative I was listening to from atheists online."
So we see the need for Christian faith to address needs of both the heart and the head. Much of contemporary Christianity is about the heart. You can't argue with someone who has an experience with God, so the argument goes. But this emotional basis for Christian faith has more to do with Schleiermacher's attempt to reconcile Kant's philosophy to Christian claims of truth that didn't seem to square with that worldview. Ironic to think our modern obsession with feelings in the Church has a lot to do with someone's problems with affairs of the head in relation to faith.
It is now nigh a few centuries now since Kant, and the prevailing worldview of the culture has changed. Thus, we need to come up with a way to address the questions that our current world is asking that is both thoughtful and faithful. At the same time, we need to address the perennial questions that invariably follow when we hit dry spells in our pilgrimage through life. We need to have a community to turn to and reasonable answers that address our feelings of loneliness, despair, frustration, suffering, or simple blase-ness. In short we need a faith that incorporates both the head and the heart, because otherwise we're only dealing with a fraction of our human existence.