Arius

The relationship between God the Father and the Son has long been a point of contention among Christians. Arius is a significant figure in this regard; he believed in the created nature of Jesus Christ and denied that his essence was the same as the Father's. In contrast, Athanasius believed in the consubstantiality of the Father and the Son. The purpose of examining the controversy between the ideas of Arius and Athanasius is to identify the consequences it left on Christianity. Therefore, the main question of this research is ‘What results did Arius's thought have and what theological effects did it leave on Christianity?’ The present study, by a descriptive and analytical method, aims to answer the main question. The most important results obtained are that Arius's ideas provoked opposition, such as the reaction of Athanasius, and created controversy, which damaged the doctrines of the Trinity, Incarnation, and Salvation. In the field of conflict between unity and trinity, it somehow led to the development of the official Christian theology, namely the Trinity.