The NT reveals that the Son is God, and the Holy Spirit is likewise God,
both separate persons from God the Father (Mt 3:16-17, 28:19).
To the contrary of the word 'separate':
You, Father, are in Me and I in You,
Jn 17:21.
God is one single unified essence. Yet, within this single unified essence of God are three separate and distinct persons of deity who are one God, each member having his part in the creation and redemption of man”
Speaking of language: Father, Son, and Spirit are distinct. But not separate.
He who sent Me is with Me; He has not left Me alone, 8:29.
Come to know and continue to know that the Father is in Me and I am in the Father, 10:38.
Indeed the Spirit of God dwells in you...Christ is in you, Rm 8:9-10.
He who is joined to the Lord is one spirit, 1 Cor 6:17.
The short answer to your question is that the term "God" as it is used in scripture is a descriptive term that defies what he is not who he is. What he is, is God. Who God is, is Jehovah.
God is not who he is, but what he is.
To the contrary:
God is a person.
Elohim said, Let Us make man in Our image, according to Our likeness......Jehovah Elohim formed man, Gen 1:26; 2:7