1. When we ask ourselves "Why do we believe in God?", the first response is provided by our faith: God has revealed himself to humanity and has entered into contact with mankind. The supreme revelation of God has come to us through Jesus Christ, God incarnate. We believe in God because God has made himself known to us as the supreme Being, the great "Existent".
However, this faith in a God who reveals himself, also finds support in the reasoning of our intelligence When we reflect, we observe that there are not lacking proofs of God's existence. These have been elaborated by thinkers under the form of philosophical demonstrations in the sense of rigorously logical deductions. But they can also take on a simpler form and, as such. they are accessible to everyone who seeks to understand the meaning of the world around him.
2. In speaking of the existence of God we should underline that we are not speaking of proofs in the sense implied by the experimental sciences. Scientific proofs in the modern sense of the word are valid only for things perceptible to the senses since it is only on such things that scientific instruments of investigation can be used. To desire a scientific proof of God would be equivalent to lowering God to the level of the beings of our world, and we would therefore be mistaken methodologically in regard to what God is. Science must recognize its limits and its inabi]ity to reach the existence of God: it can neither affirm nor deny his existence.
From this, however, we must not draw the conclusion that scientists in their scientific studies are unable to find valid reasons for admitting the existence of God. If science as such cannot reach God, the scientist who has an intelligence the object of which is not limited to things of sense perception, can discover in the world reasons for affirming a Being which surpasses it. Many scientists have made and are making this discovery.
He who reflects with an open mind on what is implied in the existence of the universe, cannot help but pose the question of the problem of the origin. Instinctively, when we witness certain happenings, we ask ourselves what caused them.How can we not but ask the same question in regard to the sum total of beings and phenomena which we discover in the world?
A supreme Cause
3. A scientific hypothesis such as that of the expansion of the un;verse, makes the problem all the more clear. If the universe is in a state of continual expansion, should not one go back in time to that which could be called the "initial moment", the moment in which that expansion began? But, whatever the theory adopted concerning the origin of the universe, the most basic question cannot be avoided This universe in constant movement postulates a Cause which, in giving it being, has communicated to it this movement, and continues to sustain it. Without such a supreme Cause, the world and every movement in it would remain "unexplained" and "inexplicable", and our intelligence would not be satisfied. The human mind can receive a response to its questions only by admitting a Being who has created the world with all its dynamism. and who continues to maintain it in existence.
4. The necessity to go back to a supreme Cause is all the greater if one considers the perfect organization which science ceaselessly discovers in the structure of matter. When human intelligence is applied with so much effort to determine the constitution and modalities of action of material particles, is it not perhaps induced to seek their origin in a superior Intelligence which has conceived the whole? In fice of the marvel of what can be called the immensely small world of the atom, and the immensely great world of the cosmos, the human mind feels itself completely surpassed in its possibilities of creation and even of imagination, and understands that a work of such quality and of such proportions demands a Creator whose wisdom is beyond all measures and whose power is infinite.
5. All the observations concerning the development of life lead to a similar conclusion. The evolution of living beings, of which science seeks to determine the stages and to discern the mechanism, presents an internal finality which arouses admiration. This finality which directs beings in a direction for which they are not responsible or in charge, obliges one to suppose a Mind which is its inventor, its creator.
The history of humanity and the life of every human person manifest a still more impressive finality. Certainly, man cannot explain to himself the meaning of all that happens to him, and therefore, he must recognize that he is not the master of his own destiny. Not only has he not made himself, but he has not even the power to dominate the of his existence. However, he is convinced that he has a destiny and he seeks to discover how he received it and how it is inscribed in his being. In certain moments he can more easily discern a secret finality which appears from a convergence of circumstances and events. Thus he his brought to affirm the sovereignty of him who has created and directs his present life.
6. Finally, among the qualities of this world which impel us to raise out gaze aloft, there is beauty.It is manifested in the various marvels of nature; it is expressed in the numberless works of art, literature. music, painting and the plastic arts.It is appreciated also in moral conduct: there are so many good sentiments, so many stupendous deeds.
Man is aware or "receiving" all this beauty, even though he cooperates by his action in its manifestation. He discovers and admires it fully only when he recognizes its source, the transcendent beauty of God
7. To all these "indications" of the existence of God the Creator some oppose the power of chance or of the proper mechanisms of matter.To speak of chance for a universe which presents such a complex organization in its elements, and such a marvellous finality in its life would be equivalent to giving up the search for an explanation of the world as it appears to us. In fact, this would be equivalent to admitting effects without a cause. It would be an abdication of human intelligence which would thus refuse to think, to seek a solution for its problems.
In conclusion, a myriad of indications impels man, who tries to understand the universe in which he lives, to direct his gaze towards his Creator. The proofs for the existence of God are many and convergent. They contribute to show that faith does not humble human intelligence, but stimulates it to reflections and permits it to understand better all the "whys" posed by the observation of reality.
(Translation and subtitles from L'Osservatore Romano, July 15 1985.)