On one of my routes to church, I pass a professionally-handpainted sign in a front yard that simply says "Have faith in reason". It makes me smile.
But we have done such violence to the word "faith" that we must pair it with reason in order to find a balanced view of our lives and of the world. At first glance, having faith could mean 'believe': believe in reason. To believe in something is to not necessarily have knowledge but to have a feeling, an intuitive sense of something. To believe is usually regarded as irrational, as going against reason and a consideration of all the facts. But reason does consider the facts and prizes them quite highly. One does not have to believe in reason but to simply make use of it.
I looked up the word "faith" and discovered that its primary meaning is loyalty: allegiance to duty or a person, or fidelity to one's promises. So in order to have faith in reason, one must remain loyal to the principles of reason: intelligence, rational thought, clarity, logic, attainment of truth and knowledge by conversation, discussion or argument as in "Come, let us reason together" - Isaiah 1: 18.
So yes, I can and do have faith in reason, I endeavor to be loyal to its principles but I also need to balance that with a loyalty to that which I cannot see, that which cannot be proven, that which is illogical, irrational, and completely mysterious. Without one, we would be heartless automatons. Without the other, brainless. It's the dance between reason and mystery, not reason and faith, that makes living so interesting, challenging, and fun.