The existence of God can be known through converging and convincing arguments derived from creation, specifically from the physical world and the human person (CCC 31). The order, beauty, movement, and contingency of the universe serve as indicators that point toward God as both the origin and the final end of all things (Rom 1:19-20). Through the light of human reason, one can arrive at a certain knowledge of God as Creator by observing His works (CCC 32).

Beyond the physical world, the human person provides evidence of God’s existence through an internal seed of eternity (CCC 31). This is manifested in a natural openness to truth and beauty, a sense of moral goodness, and a fundamental freedom. Furthermore, the innate and universal desire for happiness suggests a remembrance of a happy life that has been forgotten, a longing that can only be satisfied by God alone (CCC 1718).

From a theological perspective, God is the first cause and final end of all that exists (CCC 32). Because human beings participate in Being itself, they reveal a necessary dependence on God, who is the only being without origin or end (CCC 32). This understanding of God as the singular, unchangeable, and perfect Creator who brought the world into existence out of nothing (CCC 202, 296) establishes the foundation for the history of salvation (CCC 279-280).

While reason provides a path to certainty, faith is essential for pleasing God and involves believing in His existence and His reward for those who seek Him (Heb 11:6). Faith does not oppose reason but is facilitated by it through divine revelation, serving to confirm and enlighten the rational understanding of God’s existence (CCC 32). Through faith, individuals can acknowledge God’s invisible actions, such as the creation of the universe (CCC 292).

Ultimately, the most definitive proof of God’s existence is found in His supernatural self-revelation. Although human language is limited and cannot fully grasp the mystery of a God who transcends all creatures (CCC 42), God has chosen to make Himself known. This revelation culminates in Jesus Christ, the Word of Life made visible (1 John 1:2), who is the perfect and unsurpassable Word of God (Heb 1:1-2). Through the Holy Spirit, believers are guided to a personal relationship with the Father, acknowledging that the knowledge of the Son is obtained through the Spirit (CCC 684).