There are certain things we know. We know that the planet is round. We know that 2 + 2 = 4. We know that gravity prohibits us from floating off the ground and into Earth’s atmosphere. This knowledge is grounded on facts, scientific or logical facts, about reality and the way it operates.
We also tend to know other things. We know that we exist (unless you deny basic Cartesian philosophy). Perhaps we know that God exists. We know that there are people that love us. Or do we? On what facts are these issues grounded? Are there substantial reasons in which we know these things?
The first set of knowledge claims I listed are ones known, but ones seldom thought about or cared about. Yet we would probably all agree that we know these with certainty (or to the degree by which we as fallible creatures can possess certainty). The more important issues – the ones with dire existential interest – are the issues mentioned in the second list. We care about these because these issues provide us meaning. Yet, we are much less certain about these issues. That heightens the angst by which we as individual Selves exist and operate by.
Do we know that a person loves us? Do we know that we are actually forgiven by someone we have wronged? The possibility of these issues is not in question. It is possible that we are loved and forgiven. If something is possible, it enters the realm of probability. Again, the question becomes, “do we believe that we are loved?”
The level of uncertainty is likely to increase anxiety. But anxiety is a concept much blasphemed in our overly therapeutic culture. Anxiety is a concept by which we can find meaning for our lives. It provides us a chance to reflect on why we are anxious. Again, the things we are certain about we care little for. The things we remain uncertain of have more meaning for our lives. Do I know that God exists? And if so, does he actually love me? Do I know that _____ is the right person for me to marry? Do I know I will succeed in the career path I have chosen? The truth-claim is undetermined for these questions. More uncertainty. More anxiety. But perhaps that is beauty. Perhaps certainty in knowledge would deprive each Self of something glorious: the concept of faith.
In Concluding Unscientific Postscript, Soren Kierkegaard writes about faith and uncertainty in relation to the belief in God. Kierkegaard writes,
Faith is the most important fact in religious questions. Kierkegaard wrote: ‘If I am capable of grasping God objectively, I do not believe, but precisely because I cannot do this I must believe. If I wish to preserve myself in faith, I must constantly be intent upon holding fast the objective uncertainty, so as to remain out upon the deep, over seventy thousand fathoms of water, still preserving my faith.
Kierkegaard says that faith is survived by uncertainty. We may have faith in the truth of the claim “the planet is round” but how much faith is there in relation to the undisputed fact that science provides. Faith here is not risky, non-anxious. It probably is not faith at all. Yet to what degree of faith does one have in the undetermined truth-claim that “I am forgiven by someone who I have wronged”? We may believe that we are forgiven, but what is this belief founded in? Is it faith? Or is it knowledge? The answer involves an affirmative response to both possibilities. I am not positing that faith stands in contrast to knowledge or reason. Your belief that you are forgiven likely rests on a reputable social interaction after the offense, the communication between you and the forgiver, amongst other things. But there is always that possibility of deception or falsified behavior. So your belief rests in credibility (reason), but also in faith.
Why discuss this concept? Many are frightened by uncertainty, especially in relationships that provide meaning for our life. But uncertainty is not something that should be feared. The anxiety this produces should not be treated in therapy. It should be embraced as a sign that one is entering situations where faith can rise to the occasion and build the authentic Self. Knowledge without faith is dull. It goes unnoticed and seemingly loses impact on our lives. Uncertainty makes us consistently aware of our actions, our faults, and our need to rely on other persons for self-awareness. Uncertainty provides us with opportunities to grow, to learn, and to better ourselves. It is here faith rises. It is grounded in what we do know, but supports what we cannot know with certainty.
 I am not positing that our strive should not be toward certainty. I am not advocating ignorance or stupidity. I am, however, attempting to show that certainty may not be possible in relational situations. In these cases, we should strive to know, but where certainty lacks, our faith can rise.