God (His Existence)

● “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.”

─ST I, Q. 2, Art. 2, ad. 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."

─ST I, Q. 2, Art. 1, ad. 1.

● "The existence of God, in so far as it is not self-evident to us, can be demonstrated from those of His effects which are known to us."

─ST I, Q. 2, Art. 2.

● "As God is His own very existence and understanding, so is He His own life; and therefore He so lives that He has not principle of life."

─ST I, Q. 18, Art. 3, ad. 2.

● "The first effect wrought by God in things is existence itself, which all other effects presuppose, and on which they are based. Anything that exists in any way must necessarily have its origin from God. In all things that are arranged in orderly fashion, we find universally that what is first and most perfect in any order, is the cause of whatever follows in that order. Thus fire, which is hot in the highest degree, is the cause of heat in all other heated bodies. Imperfect objects are always found to have their origin from perfect things; seeds, for instance, come from animals and plants. But, as we proved above, God is the first and most perfect Being. Therefore He must be the cause of being in all things that have being."

─Compendium of Theology, Part I, Chap. 68.

~St. Thomas Aquinas

Virgin and Child with Sts. Dominic and Thomas Aquinas,
by Fra Angelico. Detached fresco transferred to canvas, c. 1445;
The Hermitage, St. Petersburg.