In these last chapters of Lewis’ Mere Christianity, there are two discussions on faith. According to Lewis:
Faith is the art of holding on to things your reason has once accepted, in spite of your changing moods. 1
Lewis does not seem to develop this very much, therefore, we can make a few limited remarks concerning his definition:
1) The idea of treating faith as an art does not originate in the Scriptures. Art comes from man’s work and does not give proper credit to the “author” and “perfecter” of our faith.2
2) Even if Lewis is referring to “art” as “ability,” he is still indebted to tell us where the faith comes from.
3) What does it mean to hold on to something that reason once accepted? What can reason accept apart from God’s work? Reason accepts only what the mind can see. According to Romans 8, the covenant-breaker cannot see the things of God, much less hold on to something he cannot see.
4) This entire definition is flawed from beginning to end. What Lewis appears to be defining is the garden-variety type of faith that any human is able to act. This is certainly not Biblical faith. This concept of faith Lewis proposes can just as easily be paralleled to teenage love.3
5) The definition of faith is already given to us in Scriptures. Contrary to Lewis, faith is not something you hold on that your reason has once accepted, but rather it is the assurance and conviction of things you have never seen.4 Can reason see the unseen? Notice how the author of Hebrews assumes that faith is not human-made or manipulated by human ability, rather it assumes that what we see is not made by visible hands.5