Catechism of the Catholic Church

222 Believing in God, the only One, and loving him with all our being has enormous consequences for our whole life.

223 It means coming to know God's greatness and majesty: "Behold, God is great, and we know him not." ⁴⁶ Therefore, we must "serve God first". ⁴⁷

224 It means living in thanksgiving: if God is the only One, everything we are and have comes from him: "What have you that you did not receive?" ⁴⁸ "What shall I render to the LORD for all his bounty to me?" ⁴⁹

225 It means knowing the unity and true dignity of all men: everyone is made in the image and likeness of God. ⁵⁰

226 It means making good use of created things: faith in God, the only One, leads us to use everything that is not God only insofar as it brings us closer to him, and to detach ourselves from it insofar as it turns us away from him:

My Lord and my God, take from me everything that distances me from you.
My Lord and my God, give me everything that brings me closer to you.
My Lord and my God, detach me from myself to give my all to you. ⁵¹

227 It means trusting God in every circumstance, even in adversity. A prayer of St. Teresa of Jesus wonderfully expresses this trust:

Let nothing trouble you / Let nothing frighten you Everything passes / God never changes Patience / Obtains all Whoever has God / Wants for nothing God alone is enough. ⁵²

228 "Hear, O Israel, the LORD our God is one LORD..." (Deut 6:4; Mk 12:29). "The supreme being must be unique, without equal. . . If God is not one, he is not God" (Tertullian, Adv. Marc., 1, 3, 5: PL 2, 274).

229 Faith in God leads us to turn to him alone as our first origin and our ultimate goal, and neither to prefer anything to him nor to substitute anything for him.

230 Even when he reveals himself, God remains a mystery beyond words: "If you understood him, it would not be God" (St. Augustine, Sermo 52, 6, 16: PL 38, 360 and Sermo 117, 3, 5: PL 38, 663).

231 The God of our faith has revealed himself as HE WHO IS; and he has made himself known as "abounding in steadfast love and faithfulness" (Ex 34:6). God's very being is Truth and Love.