Since the beginning of human civilization, Homo sapiens has strived to address the existence of God. In every era, humans have tried to explore the existence of God and presented their own elaborations on the concept of God. Some found the Sun to be God, while others tried to find a "divine" part in other elements of nature such as trees, animals or stars. We can note that the existence of God is a concept which is found in the very nature of the human being. The question of “seen” or “invisible” is yet another argument that populates the debate among philosophers. There is no doubt that religions have played a crucial role in establishing the existence of God. At the same time, different religions interpret the presence of God in a distinct way. In this essay, the discussion explores the views of Saint Augustine, who lived in the Roman Empire. He is a prominent figure in the world of philosophical debate (St. Thomas, 1911, pnd). The discussion develops Saint Augustine's views on the existence of God. Additionally, it examines how St. Augustine uses “reason” as a tool to support his thoughts and ideologies about the existence of God. The essay contrasts Augustine's views with those of St. Thomas on the existence of God. Finally, the essay presents a conclusion that summarizes the entire discussion.St. Augustine explained the existence of God by developing a comparison of the animate and inanimate forms of nature. He explains that animals and humans are both forms of nature, having a body and a soul; what differentiates humans is the presence of a rational mind, which makes them superior to other forms of nature. At the lowest level we can see some form of nature that exists but no life like water or stars. This f...... middle of paper ....... However, there is a certain degree of differences between the two philosophies. Augustine compelled people to explore the evidence for existence by analyzing their perception of reason. On the other hand, Thomas presented a number of scientific reasonings like motion and gradation to explain the existence of God. Thomas's philosophy explains the concept in several dimensions; he concludes the arguments and reasons using five distinct approaches. Thomas's philosophy is therefore detailed. From the discussion, it can be concluded that the existence of God can be proven and developed through logical reasoning. They can be proven by seeking answers to our daily questions such as: what can be greater than our reason, which dictates the solar system to act like an animated body? The evidence may not have physical existence, but it is supported by the physical elements of nature..