Why is Arianism classified as a Christological heresy?

Arianism is classified as a Christological heresy primarily because it misrepresents the nature of Christ, specifically in relation to His divinity. Arianism, originating from the teachings of Arius, contended that Jesus Christ, as the Son of God, was not co-eternal with the Father and was instead a created being. This belief fundamentally undermines the orthodox understanding of the nature of Christ as fully divine and fully human, as expressed in key doctrinal statements established by the first ecumenical councils, such as the Council of Nicaea in 325 AD.

When discussing Christology, it is essential to affirm that Christ is both fully God and fully human, a doctrine upheld by the early Church. Arianism's assertion that the Son is subordinate to the Father directly contradicts this crucial tenet. By suggesting that the Son of God was not eternal and thus not fully divine, Arianism misrepresents the essential character of Christ, leading to significant theological implications regarding the nature of salvation, the Trinity, and the relationship between God and humanity.

The other options, while relevant to discussions about Christology and ecclesiastical authority, do not capture the specific nature of Arianism's deviation from orthodox Christology