The Balanced Truth of the Triune God
When it comes to understanding the nature of God, it is important to avoid going to extremes. Two examples of extremes are Modalism and Tritheism. Modalism stresses the side of God being one to a heretical extreme by denying the coexistence and coinherence of the three of the Godhead. Tritheism, on the other hand, stresses the side of God being three to a heretical extreme by teaching that the Father, the Son, and the Spirit are three Gods.
The Bible, however, is not at either of these extremes. It stands in the center, testifying of the twofoldness of the truth of the Divine Trinity. The Bible clearly, definitely, and repeatedly states that there is only one God (1 Cor. 8:4; Isa. 44:6, 8; 45:5-6, 21-22; 46:9; Psa. 86:10). So, it is a great heresy to say that there are three Gods.
On the other hand, the Bible also teaches the existence of the Father, the Son, and the Spirit all existing at the same time and under the same conditions. These three are eternal. Isaiah 9:6 states that the Father is eternal, Hebrews 1:12 and 7:3 indicate that the Son is eternal, and Hebrews 9:14 speaks of the eternal Spirit. We should believe in the coinherence and coexistence of the three of the Godhead, that is, that the Father, the Son, and the Spirit all exist at the same time and under the same conditions.
It is important to be balanced and avoid the heretical extremes of both modalism and tritheism. When we say that the Son is the Father (Isa. 9:6) and the Lord is the Spirit (2 Cor. 3:17), we are simply quoting the Bible. We should believe all the verses in the Bible which reveal the eternal coexistence and coinherence of the three of the Godhead.
It is important to remember that the Divine Trinity is a mystery which far transcends our mental apprehension. We may not fully understand how the Father, the Son, and the Spirit can be three and at the same time still be one, but we should still believe in their existence and coexistence as stated in the Bible.