Faith is precisely the contradiction between the infinite passion of the individual's inwardness and the objective uncertainty. If I am capable of grasping God objectively, I do not believe, but precisely because I cannot do this I must believe.".
In this quote, Soren Kierkegaard is saying that Faith is a gut feeling, an emotion, and not an idea, something that comes from the mind, through a thought process. According to Kierkegaard, Faith is the confliction of this gut feeling, that you feel with burning absolution, and the inability to prove the object of your faith. If Kierkegaard is right, then thinking isn't a part of faith, if you reasoned through your faith you may well come to the conclusion that your faith is unsupported by any knowledge or truths, and that if you were using reason, you would have to abandon your faith. Because the entire point of faith is that it is held against all odds, then thinking must have been abandoned, as thinking involves, or leads to questioning your faith, and if you are questioning it, you do not truly have faith.
In the case of religious faith, it is the majority of cases now that people have not thought about their faith, and have only come to believe in it due to the culture of their society, and the way in which they are brought up. This is faith without thought, no reasoning has been used to come to a conclusion about why this faith should be held, it is just done so. A. Plantinga argues that this belief in god is a "properly basic belief" and that it is ok to believe something without thought or reason, but only until someone wishes to disprove, or opposes that belief, then rational argument is needed to justify belief in it.
Another argument for the case that faith begins precisely where thinking leaves off is in the history books. Ancient Civilisations, and other people of the past, used religion and faith as a way of explaining the inexplicable, they couldn't understand something, so they invented Gods or Myths to save them from thinking about things such as how the world was created, how the sun rose every day, and the reason for the seasons.