God

WE BELIEVE THAT GOD EXISTS
We believe that God, the Supreme Being and Creator of all things, exists. We believe He is eternal, having no beginning and no end. We believe He is all-powerful (omnipotent), all-knowing (omniscient), and all-present (omnipresent). We believe He created mankind in His image and likeness (cf. Gen. 1:27) and that He desires the salvation of all people (cf. 1 Tim. 2:4).

WHY DO WE BELIEVE THAT GOD EXISTS
As Saint Paul tells us in his Letter to the Romans, we do not need to turn to religious sources to know that God exists. We find evidence of His existence merely in viewing the wonder of Creation, His handiwork.

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 invisible nature, namely, his eternal power and deity, has been clearly perceived in the things that have been made. So they are without excuse (Rom. 1:19-20).

Elaborating on this idea, Saint Thomas Aquinas, the brilliant Christian theologian of the Middle Ages, argued for belief in God from reason alone, supplying the following five proofs for this in his Summa Theologica (1265-1274 A.D.):

1. The Argument from Motion. We can perceive with our senses that the physical world consists of objects acting upon one another. Reason and the laws of physics dictate that a First or Unmoved Mover had to exist at the beginning to set everything else into motion.

2. The Argument from Efficient Cause. Since a thing cannot cause itself, all things must have a cause: a thing which came before it to set it into motion. This dictates the necessity for a First or Uncaused Cause at the beginning.

3. The Argument from Necessary Being. Since objects in the universe come into and pass out of existence, it is possible for these things to exist or not to exist. Since it is also true that a thing cannot come into being on its own, a First and Necessary Being had to exist to call all others into existence.

4. The Argument from Gradation. Through our senses we can observe gradations of goodness in the world. We can see that objects become increasingly more complex as we move up the chain from inanimate matter to living organisms, and ultimately to man himself. Logically, then, a Perfect Being who is the highest good must exist at the top of the process.

5. The Argument from Design. Our senses affirm there is an order which governs all things in the physical universe. This order cannot exist by coincidence, but must be the result of a grand design. This necessitates the existence of an Ultimate Designer.

Even though we can know that God exists through reason and observation, we cannot fully know Him in this way. This is because He is infinite and we are finite. The Fall, moreover, has clouded our intellect and injured our relationship with Him. For us to know all that God desires us to know about Him for salvation, therefore, it was necessary for Him to come and reveal Himself to us. Therefore, we know of God partially through reason, and more fully through revelation.

WE BELIEVE THERE IS ONE GOD
The Catholic faith is monotheistic, meaning we believe in one God, not many.

WHY DO WE BELIEVE THERE IS ONE GOD?
Sacred Scripture proclaims the truth that there is one God, not many. "I am the first and I am the last; besides me there is no god" (Isa. 44:6). We also find this truth expressed in the writings of the Early Church Fathers, such as Aristides of Athens, who wrote in 125 A.D.: "[Christians] acknowledge God, the Creator and Maker of all things, in the only-begotten Son and in the Holy Spirit. Other than Him, no god do they worship" (Apology 15). Finally the belief in one God agrees with reason. For if God is perfect and the Supreme Being, then He cannot have a rival.  "The supreme being must be unique, without equal ...," says Tertullian. "If God is not one, he is not God' (Adv. Marc., 1:3:5)."

WE BELIEVE THAT GOD IS THREE IN ONE (THE BLESSED TRINITY): We believe the one true God consists of three divine, co-equal and co-eternal persons: the Father, the Son, and the Holy Spirit.

WHY DO WE BELIEVE GOD IS THREE IN ONE (THE BLESSED TRINITY)? God's Trinitarian nature is implied in the Old Testament and revealed by Jesus Christ in the New. That God speaks in the first person plural in Genesis indicates there is more than one divine person present in Him. "Let us make man in our image, after our likeness" (Gen. 1:26; cf. 3:22, 11:7). Likewise, Abraham's three mysterious visitors, who are referred to singularly as "the LORD," point to the Trinity (Gen. 18:1). In the New Testament, the Archangel Gabriel mentions the three divine persons in his Annunciation to the Virgin Mary (making Mary the first person to believe in the Trinity, the first Christian) (Luke 1:35). The Trinity is clearly manifest in the scenes of Christ's Baptism (Matt. 3:13-17) and Transfiguration (Matt. 17:1-6), and is mentioned by name by the Lord in the Great Commission to the Apostles (Matt. 28:19).

We also find Trinitarian belief in the historical writings of the early Church Fathers. The first written usage of "Trinity," in fact, is found in a letter of Saint Theophilus, the Bishop of Antioch, in about 181 A.D. "The three days before the luminaries were created [in Genesis]," he writes, "are types of the Trinity: God, his Word, and his Wisdom" (To Autolycus 2:15).

Finally, while the mystery of the Trinity cannot be discerned through reason alone, there is a logic to it. For it could be argued that if God had not existed as a plurality of persons from all eternity it would have been impossible for Him to love since love requires an object of affection. Pope Saint John Paul the Great used the image of the family to describe God, "a community of persons united in love" (Letter to Families 6). Thus, just as man in himself is an image of God, so also the human family is made in the divine image.

Learn more about the Trinity in the Catechism of the Catholic Church.