It is often claimed that religious faith is mere simplistic credulity and that theology is verbosity that tries to affirm things that cannot be proven. Although these beliefs are very common, they are still wrong. In reality the simpletons are the ones who assent to that caricature of faith that they have carelessly accepted. To correct this error it is necessary to define what human reason is, and the natural senses that feed it. It is also necessary to specify what are the reasonable foundations of true faith, and how the internal coherence of Christian beliefs and their historical development, present sufficient reasonable evidence of their supernatural origin. Once that barrier is overcome and we understand that faith arises from reason, we can explain what the Christian definition of faith is. The beautiful expression of Saint Thomas More (1478-1535) summarizes very well the relationship between Christian reason and faith:
“In the soul of man, reason must govern as a sovereign, but it can only reign when it loyally submits itself to faith to serve God.”
Fides et Ratio 1 — “Faith and reason are like the two wings with which the human spirit rises towards the contemplation of the truth. God has placed in the heart of man the desire to know the truth and, in short, to know Him so that, knowing and loving him, he can also reach the full truth about himself. “
Exodus 33: 18-20 — Moses said, ‘Show me your glory, I pray.’ And he said, ‘I will make all my goodness pass before you, and will proclaim before you the name, “The Lord”; and I will be gracious to whom I will be gracious, and will show mercy on whom I will show mercy. But’, he said, ‘you cannot see my face; for no one shall see me and live.’
Psalms 27: 8-9 — “Come,” my heart says, “seek his face!” Your face, Lord, do I seek. Do not hide your face from me. Do not turn your servant away in anger, you who have been my help. Do not cast me off, do not forsake me, O God of my salvation!
Psalms 63: 2-3 — So I have looked at you in the sanctuary, beholding your power and glory. Because your steadfast love is better than life, my lips will praise you.
Juan 14: 8 –”Lord, show us the Father and that is enough for us” said Phillip.
1 John 3: 2 – “Beloved, we are God’s children now; what we will be has not yet been revealed. What we do know is this: when he[a] is revealed, we will be like him, for we will see him as he is. 3 And all who have this hope in him purify themselves, just as he is pure.”
Human beings perceive the reality of the material universe by means of the physical senses namely: sight, hearing, taste, smell, and touch.
Through the senses, human intelligence obtains information that is used to discern the validity of human actions. The sight allows us to see obstacles or dangers in our path and also reveals what is necessary for our survival. Our olfactory sense alerts us not to eat something that smells bad, or to detect the proximity of a dangerous fire, and also allows us to enjoy the pleasant scents of nature around us. That is the case with all the other human senses that feed our reason with useful information so that, by making good use of them, we can live and prosper in the material world.
Reason receives what the senses grasp, judges reality according to that information, using intelligence to know parts of that reality that are not directly accessible to the senses, thus separating what is good from what is bad.
Just as the senses feed reason with information, reason in turn nourishes the experience by keeping everything we learn in memory. The combination of meaning, reason and experience makes human intelligence go beyond the merely apparent, gradually reaching a better understanding of the reality that surrounds it. However, human reason is sometimes fallible and thus man frequently observes certain phenomena but fails to deduce exactly the right causes. That is why we need the assistance of divine grace in matters of faith.
If reason is not easy to define, the definition of faith is even more elusive. It is understood as natural faith to simply believe in someone’s word (our parents, friends, neighbors, etc.) confidence in the integrity of something (a bridge, an airplane, a newspaper, etc.)
Confidence in the knowledge accumulated by others is natural faith. When assisted by reason, we call it reasonable faith. To believe in the word of someone with a good reputation is reasonable. To believe in the word of incapable or deceitful persons is unreasonable.
When we believe what was supernaturally revealed to Christians, for example that “Christ is the Son of God” we believe with supernatural faith. Our natural senses cannot physically verify the divine filiation of Christ, but we accept it because we have confidence in the source, which can be the Magisterium of the Church, Sacred Tradition, or Sacred Scripture.
Matthew 27: 50-54 — Then Jesus cried again with a loud voice and breathed his last. At that moment the curtain of the temple was torn in two, from top to bottom. The earth shook, and the rocks were split. The tombs also were opened, and many bodies of the saints who had fallen asleep were raised. After his resurrection they came out of the tombs and entered the holy city and appeared to many. Now when the centurion and those with him, who were keeping watch over Jesus, saw the earthquake and what took place, they were terrified and said, “Truly this man was God’s Son!”
The Roman centurion, no being a believer, could clearly appreciate the coincidence of powerful natural phenomena with the last breath of Jesus. He knew that Jesus “had declared to be the Son of God” among other things. The hardened soldier soon “put two and two together” adding what he already knew and what his own senses were revealing to him. It was then that his reason cleared the way for his faith, prompting him to believe that Christ was “really the Son of God” without a doubt.
The terror of that moment was not necessary to reinforce the faith of those believers who accompanied Christ on Calvary. The Virgin Mary, the other women, and St. John had already grown in faith by listening to the teachings of Jesus and seeing innumerable miracles and supernatural events. For them, those terrifying moments were the logical continuation of what they had already learned, understood, and accepted: that Jesus was the Son of God.
We understand and agree with our intellect to the truths revealed by God, ordered by theology in a coherent whole that comes to us by the grace of God.
Hebrews 1: 1-3 — Long ago God spoke to our ancestors in many and various ways by the prophets, but in these last days he has spoken to us by a Son, whom he appointed heir of all things, through whom he also created the worlds. He is the reflection of God’s glory and the exact imprint of God’s very being, and he sustains all things by his powerful word. When he had made purification for sins, he sat down at the right hand of the Majesty on high,
2 Corinthians 6: 6-8 — By purity, knowledge, patience, kindness, holiness of spirit, genuine love, truthful speech, and the power of God; with the weapons of righteousness for the right hand and for the left; in honor and dishonor, in ill repute and good repute. We are treated as impostors, and yet we are true.
As the truths revealed by God can not be verified directly by our limited senses, we must voluntarily agree with our intellect, trusting in the source provided by the grace of God, adhering to the revealed truth that we can’t always fully understand. Two things help us: the first is the source of that truth; and the other is the internal coherence of the divine message that—although we can not apprehend them naturally — we can accept them out of respect for God, the source of revealed truth. Theology presents these truths in an orderly fashion, revealing an internal coherence that is humanly impossible to falsify. For example, the theological coherence of the revelation in Sacred Scripture, Sacred Tradition and the Magisterium of the Church given to different men and women throughout the centuries, is irrefutable proof of their supernatural origin.
Romans 4: 1-3 — What then are we to say was gained by Abraham, our ancestor according to the flesh? For if Abraham was justified by works, he has something to boast about, but not before God. For what does the scripture say? “Abraham believed God, and it was reckoned to him as righteousness.”
The act of assenting intellectually to revealed truth comes from reason. That is why we can say that faith is united to it and feeds on it. Thus the act of believing results in merit for the believer. In the case of Abraham, St. Paul explains that the patriarch’s trust was meritorious to the point that God considered him a righteous person, that is, someone perfect, even though Abraham was not naturally perfect.
The experience of Abraham with God was obviously supernatural but it was also beneficial for him. Once Abraham’s human intellect was satisfied by that experience, he concluded that God was good and beneficent. That is why God is evidently worthy of credit.
God, on the other hand, understood how much Abraham trusted in Him, and recognized the merit of the man who believed in Him. That principle continues to operate: faith in God makes the believer righteous and God, who is a benefactor, rewards that faith with salvation. Christian thought recognizes that both faith and reason are gifts of God to man. We can trust the reason rightly ordered to faith so that it responds to the concerns of the human heart that wants to know who we are, what our origin, the limits and purpose of good and evil, and our eternal destiny.
In these first decades of the third millennium, a certain distrust of human reason has developed—this attitude has been growing for many centuries, since the advent of the so-called eighteenth-century Illuminism. That is the origin of what Pope Benedict XVI called “the dictatorship of relativism” and the virtual abolition of objective truth. The results are clear: the twentieth century has been one of the most violent in history and certainly the century in which irrational, extreme, and nihilistic ideas have had the most disastrous influence. The situation has worsened to the extent that humanity tries to create systems of thought that abandon faith in favor of what purports to be pure reason. To facilitate this process, some argue that faith is a denial of reason, a superstition that obscures the intellect of man. They confuse faith with credulity and try to present it as a harmful element. On this irrational project, the Christian author T. S. Eliot wrote: “The World is trying the experiment of attempting to form a civilized but non-Christian mentality. The experiment will fail; but we must be very patient in awaiting its collapse; meanwhile redeeming the time: so that the Faith may be preserved alive through the dark ages before us; to renew and rebuild civilization, and save the World from suicide.”  In the same tone, the Christian apologist C. S. Lewis says: “Perhaps I am asking impossibilities. Perhaps, in the nature of things, analytical understanding must always be a basilisk which kills what it sees and only sees by killing. But if the scientists themselves cannot arrest this process before it reaches the common Reason and kills that too, then someone else must arrest it.” 
Denying that faith is as a useful element for the realization of man—who naturally wishes to live for, and know the truth—leaves humanity in darkness, where it will be more easily manipulated. With dead faith, and reason questioned, modern man is reduced to obeying the directives of power exercised purely by force. The obvious objective of those dark forces is the total abolition of human freedom. Without freedom, man can no longer assent with dignity to the revelation of faith and is violently separated from divine guidance and its moral, intellectual, cultural and even biological dimensions.
Following the reasoning of T. S. Eliot in this sense, Christians today must cultivate reason since that is the place where they can encounter non-believers and bring them to faith. God has enabled man to understand the spiritual, the divine, through the material.
Wisdom 13: 4-9 — And if people were amazed at their power and working, let them perceive from them how much more powerful is the one who formed them.
For from the greatness and beauty of created things comes a corresponding perception of their Creator. Yet these people are little to be blamed, for perhaps they go astray while seeking God and desiring to find him. For while they live among his works, they keep searching, and they trust in what they see, because the things that are seen are beautiful. Yet again, not even they are to be excused; for if they had the power to know so much that they could investigate the world, how did they fail to find sooner the Lord of these things?
Romans 1: 18-22 — For the wrath of God is revealed from heaven against all ungodliness and wickedness of those who by their wickedness suppress the truth. For what can be known about God is plain to them, because God has shown it to them. Ever since the creation of the world his eternal power and divine nature, invisible though they are, have been understood and seen through the things he has made. So they are without excuse; for though they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their senseless minds were darkened. Claiming to be wise, they became fools.
How do we understand this? The human capacity to verify through reason all that the senses communicate, is limited by the complexity of creation and the short natural life of man. The human being is obliged to accept the knowledge accumulated by those who preceded him in the search for the truth. That is really a form of faith: trust—guided by reason—in the capacity and wisdom of those who lived before us. That is why we understand that faith is an integral part of right reason. Faith and reason need each other because it is impossible, it is “foolishness”, to have faith in something that right reason does not confirm. The entire creation serves as a guide to reason, bringing to faith those who seek the truth.
Faith and reason are like two wings
Philosophy (for reason) and theology (for faith) are instruments that assist those who seek the fullness of truth. The first receives the light of truth through the study of creation in all its complexity. The second receives that same light by studying divine revelation.
Much can be written about this subject that is really inexhaustible, but summarizing we can say that both faith and reason are of divine origin, they are gifts of God to man so that man can find him even though God can’t be seen directly. Faith and reason are like the two sides of the rift in which God protected Moses from the intensity of encountering the Divinity, allowing the prophet to contemplate the glory of God indirectly, understanding the enormity of the divine reality without being consumed. In the encounter between the human and the divine, faith and reason serve man without contradictions, allowing our weak humanity to contemplate the glory of the Creator understanding the happy purpose and destiny that the Creator has prepared for us.
As it is logical to expect, God has given us a way to follow this process. The ultimate example is Jesus Christ, who is God and man. We also have the example of Mary of Nazareth, prefigured in the Old Testament as Wisdom. It is Mary who in very few words expressed the perfect relationship between faith and reason: “let it be with me according to your word.”
Luke 1: 38 — Then Mary said, “Here am I, the maidservant of the Lord; let it be with me according to your word.” Then the angel departed from her.
In that scene, the perfect human nature of Mary receives a divine revelation through a spiritual being, an angel. Mary trusts and gives herself completely to the will of God. The limited knowledge of Mary presented many difficulties to her reason because she did not know how that child would be born, what would happen to her when her pregnancy was known by the community, etc. The acceptance of Mary is a perfect example of the subordination of reason tof faith. Over time, Mary was able to fully understand the reasons that faith presented to her condensed in the words of the angel. Following Mary’s example is essential for us. Our reason must assent to faith to be elevated and perfected, thus arriving at a full realization of our humanity in light of divine revelation.
Please remember to pray for (and if possible donate to) this ministry during Lent season.
 Encyclical Fides et Ratio of Pope St John Paul II, given in Rome on September 14, 1998.
 Thomas Stearns Eliot, Thoughts After Lambeth, 1931.
 Clive Staples Lewis, The Abolition of Man, 1945.