✟ The Unity and Trinity of God ✟
The Existence of God
Revealed Truth (Defined Dogma)

God, our Creator and Lord, can be known with certainty,
by the natural light of reason from created things.

Lay Catechist Notes/Associated Doctrines
    Every human being has been naturally endowed with a "God given" and intuitive knowledge of the true existence of God. To not believe there is a God is to deny one's own self-knowledge and self-awareness - in other words, a denial to accept what the mind actually knows to be true and the human senses are constantly confirming.

    Associated Catholic Doctrine(s):
    1. "The existence of God can be proven by means of causality." (sententia fidei proxima)
Divine Revelation (Scriptural Proof)
  • 11This commandment, that I command thee this day is not above thee, nor far off from thee: 12Nor is it in heaven, that thou shouldst say: Which of us can go up to heaven to bring it unto us, and we may hear and fulfil it in work? 13Nor is it beyond the sea: that thou mayst excuse thyself, and say: Which of us can cross the sea, and bring it unto us: that we may hear, and do that which is commanded? 14But the word is very nigh unto thee, in thy mouth and in thy heart, that thou mayst do it. (Deuteronomy 30:11-14)
  • 1But all men are vain, in whom there is not the knowledge of God: and who by these good things that are seen, could not understand him that is, neither by attending to the works have acknowledged who was the workman: 2But have imagined either the fire, or the wind, or the swift air, or the circle of the stars, or the great water, or the sun and moon, to be the gods that rule the world. 3With whose beauty, if they, being delighted, took them to be gods: let them know how much the Lord of them is more beautiful than they: for the first author of beauty made all those things. 4Or if they admired their power and their effects, let them understand by them, that he that made them, is mightier than they: 5For by the greatness of the beauty, and of the creature, the creator of them may be seen, so as to be known thereby. 6But yet as to these they are less to be blamed. For they perhaps err, seeking God, and desirous to find him. 7For being conversant among his works, they search: and they are persuaded that the things are good which are seen. 8But then again they are not to be pardoned. 9For if they were able to know so much as to make a judgment of the world: how did they not more easily find out the Lord thereof? (Wisdom 13:1-9)
  • 20For the invisible things of him, from the creation of the world, are clearly seen, being understood by the things that are made; his eternal power also, and divinity: so that they are inexcusable. (Romans 1:20)
  • 14For when the Gentiles, who have not the law, do by nature those things that are of the law; these having not the law are a law to themselves: 15Who shew the work of the law written in their hearts, their conscience bearing witness to them, and their thoughts between themselves accusing, or also defending one another, (Romans 2:14-15)
  • 14And saying: Ye men, why do ye these things? We also are mortals, men like unto you, preaching to you to be converted from these vain things, to the living God, who made the heaven, and the earth, and the sea, and all things that are in them: 15Who in times past suffered all nations to walk in their own ways. 16Nevertheless he left not himself without testimony, doing good from heaven, giving rains and fruitful seasons, filling our hearts with food and gladness. (Acts 14:14-16)
Catechism of the Catholic Church
  • 36 "Our holy mother, the Church, holds and teaches that God, the first principle and last end of all things, can be known with certainty from the created world by the natural light of human reason." Without this capacity, man would not be able to welcome God's revelation. Man has this capacity because he is created "in the image of God".
  • 47 The Church teaches that the one true God, our Creator and Lord, can be known with certainty from his works, by the natural light of human reason (cf. Vatican Council I, can. 2 # 1: DS 3026),
  • 286 Human intelligence is surely already capable of finding a response to the question of origins. The existence of God the Creator can be known with certainty through his works, by the light of human reason, even if this knowledge is often obscured and disfigured by error. This is why faith comes to confirm and enlighten reason in the correct understanding of this truth: "By faith we understand that the world was created by the word of God, so that what is seen was made out of things which do not appear."
Ecumenical Council Documents
  • 1st General Council of the Vatican (1869)
    • Chapter 2 On revelation
      • "The same Holy mother Church holds and teaches that God, the source and end of all things, can be known with certainty from the consideration of created things, by the natural power of human reason : ever since the creation of the world, his invisible nature has been clearly perceived in the things that have been made.
    • Canons - 2. On Revelation
      • If anyone says that the one, true God, our creator and lord, cannot be known with certainty from the things that have been made, by the natural light of human reason: let him be anathema.
Papal Encyclical Documents
  • Humanum Genus (1884) - The Human Race - Leo XIII
    • Section 17
      • "Hence it happens that they no longer consider as certain and permanent those things which are fully understood by the natural light of reason, such as certainly are - the existence of God, the immaterial nature of the human soul, and its immortality..." (Referring the "naturalists" of that day).

  • Humani Generis (1950) - The Human Race - Pius XII
    • "2. It is not surprising that such discord and error should always have existed outside the fold of Christ. For though, absolutely speaking, human reason by its own natural force and light can arrive at a true and certain knowledge of the one personal God, Who by His providence watches over and governs the world, and also of the natural law, which the Creator has written in our hearts, still there are not a few obstacles to prevent reason from making efficient and fruitful use of its natural ability."

      "It is well known how highly the Church regards human reason, for it falls to reason to demonstrate with certainty the existence of God, personal and one; to prove beyond doubt from divine signs the very foundations of the Christian faith; to express properly the law which the Creator has imprinted in the hearts of men; and finally to attain to some notion, indeed a very fruitful notion, of mysteries."


  • Ad Petri Cathedram (1959) - To the Chair of Peter - John XXIII
    • "7. And yet, God gave each of us an intellect capable of attaining natural truthIf we adhere to this truth, we adhere to God Himself, the author of truth, the lawgiver and ruler of our lives. But if we reject this truth, whether out of foolishness, neglect, or malice, we turn our backs on the highest good itself and on the very norm for right living."
      "8. As We have said, it is possible for us to attain natural truth by virtue of our intellects. But all cannot do this easily; often their efforts will result in a mixture of truth and error. This is particularly the case in matters of religion and sound morals."
Fathers and Doctors of the Church Documents
  • Summa Theologica - The One God (1265) - The Highest Study of God - Thomas Aquinas
    • "Whether the Existence of God Is Self-Evident?"
      • Reply to Objection 1: "To know that God exists in a general and confused way is implanted in us by nature, inasmuch as God is man's beatitude. For man naturally desires happiness, and what is naturally desired by man must be naturally known to him. This, however, is not to know absolutely that God exists; just as to know that someone is approaching is not the same as to know that Peter is approaching, even though it is Peter who is approaching; for many there are who imagine that man's perfect good which is happiness, consists in riches, and others in pleasures, and others in something else."
    • "Whether It Can Be Demonstrated That God Exists?"
      • "Reply to Objection 1: The existence of God and other like truths about God, which can be known by natural reason, are not articles of faith, but are preambles to the articles; for faith presupposes natural knowledge, even as grace presupposes nature, and perfection supposes something that can be perfected. Nevertheless, there is nothing to prevent a man, who cannot grasp a proof, accepting, as a matter of faith, something which in itself is capable of being scientifically known and demonstrated."