The fact that we are directed to behave virtuously through reason may make it mysterious why Divine instruction is necessary at all. Here it is good to remember that faith is not the constriction of reason by blind dogma, as our own time so often views it. Rather it is the unshackling of reason by grace, and its enlargement by the data of Revelation. Reason is not only set free from sin, but also given more to work with.
But the fact that Revelation exceeds what we could have figured out for ourselves introduces a puzzle. How can it be reasonable to submit to help from beyond human reason?
In at least five ways.
1. Since the reality, power, wisdom, and goodness of God can be philosophically demonstrated, it is reasonable to consider Revelation possible.
2. Since, even though we have a natural inclination to seek the truth about Him, our finite minds, still further weighed down by self-deception, could never equal His infinite mind, it is reasonable to consider Revelation necessary.
3. Since He who gave us the inclination to seek Him must desire us to find Him, it is reasonable to consider Revelation likely.
4. Since the record of Revelation is well-attested by miracles, it is reasonable to believe Revelation authentic.
5. Since faith is accompanied by the experience of grace, it is reasonable to believe Revelation confirmed. The Psalmist cries, “O taste and see that the Lord is good!” Expressing the same thought in a different key, St. Paul exhorts, “test everything; hold fast what is good.”
By the light of Revelation, the mind is not only able to see more clearly those things that lie within its natural reach, but is also able to understand and explain many other features of the world that would otherwise have remained utterly baffling, such as why our hearts are so divided against themselves. When reason rejects Revelation, it is not being more true but less true to itself; only illuminated by God can it come into its own.
The hope of faith is that one day our thoughts may be lit not only by the reflected light of Revelation, but by the direct illumination of face of God Himself: That although now our minds only smolder, one day they will blaze with fire.