The Partially Examined Life (Citizens): (Protected Content)
On Mere Christianity (1952), where Lewis presents the moral argument for the existence of God and present Christianity as uniquely solving the human conundrum that our moral phenomenology presents, i.e. that the moral law is real in us yet we can never fulfill it. Once you’re on board with that reasoning, faith is a matter of sticking to your realization even though Christianity’s moral rules are extremely stringent.