In Trinitarian theology, theologians describe the Trinity as possessing an essence or being, and the identity of the Trinitarian God is rooted in this essence. In some forms of non-Trinitarian theology (acknowledging that there are many varieties), it is the Father whose identity is strictly identified as God in terms of essence. Both Trinitarian and non-Trinitarian perspectives, however, appear to agree on the functional usage of the term "God." This functional sense refers to a being's ability to exercise divine power and knowledge in roles such as absolute rulership—both in heaven and on earth—providing care, teaching, revealing or concealing truth, saving, performing miracles, and so on. In both the Father and Jesus, these functions can be seen at work.
In Trinitarian theology, the being of the Trinity is capable of exercising these functions, but there is more to this being than just function; there is essence as well. In non-Trinitarian theology, it is acknowledged that the Father exercises these functions to the fullest degree, while the Son does so to a lesser degree. However, in both traditions, it is crucial not to confuse function with identity when using the term "God." Failing to recognize the distinction between these two uses—identity and function—often leads to misunderstandings and exaggerated claims. This confusion can result in one person accusing another of heresy or unbelief, simply because they have misunderstood how the other person is using the term "God" in their theological statements.
