Augustine's theory of trinity

The Trinity doctrine, which expresses the divinity of the Father, Son and Holy Spirit, which is controversial of Christianity but also forms its basis, is a doctrine that began to take shape in the third and fourth centuries. Although the idea of the Trinity is primarily associated with Christianity, in pre-Christian societies it had also emerged as triple gods, gods with a single head or gods with three faces in a single head. The Trinity traced in the Bible was obtained only inferentially because it does not exist as word or doctrine in either the Old Testament or the New Testament. The development process of the Trinity, which is the cornerstone of Christianity, brought the formation of the history of councils with it. In this study, in order to understand the doctrine of the Trinity, which began to take shape in the third and fourth centuries, I tried to examine the way and method used by Saint Augustine, who formed the first phase of Western Christianity. Some theological and ontological concepts such as "essence" (Gr. Ousia) and "person" (Gr. Hypostasis), Augustine placed these concepts in his own understanding. Therefore, Augustinus tried to understand the Trinity doctrine before him and to overcome the problems it brought with it by using the method of analogy. The aim of this thesis is to examine the historical development of the Trinity, to understand the problem-solution phase through the method of Saint Augustine, which has been the turning point of Western Christianity, and to investigate the effect of philosophy in the development phase of Christianity. Keywords: Analogy, Augustine, Essence, Trinity