Homo capax Dei is a thought that intrigues the man of the past as well as today. That is why the possibility of natural knowledge of God is the subject of this paper. There are many ways to prove the existence of the Creator of the whole world, and thus of man, and this paper started from the encyclical Fides et ratio of Pope John Paul II. In that encyclical, the relationship between faith and reason, their contradictions and links, was summarized, and the question of truth was dealt with in a special way – what the truth is, what it is like to know and recognize the Truth written with a capital letter. It was necessary to return to history, so the link was noticed in the content of the encyclical Aeterni Patris of Pope Leo XIII. When questioning the defining of truth, the great man of Christian philosophical thought – Thomas Aquinas was inevitably recognized. Truth and proofs of God's existence are the most common themes of Aquinas's philosophy, therefore, the support for this thesis was based on the necessity of the connection between faith and reason, through his conclusions. Pope John Paul II calls St. Thomas a „lover of truth“ because with his insights and perseverance he tried to penetrate to the very core of universal, objective and transcendent truth. The paper contains four essential parts. The first deals with the representation of the thought of Thomas Aquinas in the encyclical Fides et ratio, the second chapter emphasizes truth as the central thought of Aquinas, the third part talks about the foundation of God's existence and the obstacles to that possible knowledge, and the fourt chapter thoroughly deals with Thomas's five paths that lead to the proof of God's existence. In the end, it was possible to conclude that natural knowledge of God is possible, and that faith is not an obstacle to human reason regarding the knowledge of the Creator, moreover, that man can communicate with Him.