A failure to understand something does not mean it is irrational. It may simply mean that it lies on the far side of our limited abilities to take things in and make complete sense of them.

Within each of us exists the image of God, however disfigured and corrupted by sin it may presently be. God is able to recover this image through grace as we are conformed to Christ. Just as the figure of David lay hidden within the marble, discernible only to the eye of its creator, so the image of God (however tarnished by sin) lies within us, see and known by God Himself. Yet God loves us while we are still sinners. He doesn't have to wait until we stop sinning. Acceptance of His love is a major step along the road that leads to our liberation from the tyranny of sin.

The reading of literature opens our eyes, offering us new perspectives on things that we can evaluate and adopt.

At Oxford University, the certainties of my atheist faith (and atheism is a faith) began to crumble

For Calvin, the creation reflects its Creator at every point. Image after images flashed in front of our eyes, as Calvin attempts to convey the multiplicity of ways in which the creation witnesses to its Creator: it is like a visible garment, which the invisible God dons in order to make himself known; it is like a book in which the name on the Creator is written as its author; it is like a theater, in which the glory of God is publicly displayed; it is like a mirror, in which the works and wisdom of God are reflected.

For Luther, it (faith) is an undeviating, trusting outlook appointment life, a constant stance of the trustworthiness of the promises of God.

Rational argument does not create belief, but it maintains a climate in which belief may flourish.