A skeptic mocking the Biblical Trinity asked in jest:
Was it another God called the Father who was dwelling in another God called Jesus Christ or God called the Father who was dwelling in a man called Jesus Christ?
NO, the Father, the Son, the Spirit are One-God expressed in three-distinct Persons with individual will and purpose in the Realm of Time beginning with Genesis 1:1 where our Creator affirmatively chose to use the Name “Elohim” in “The Beginning” as a plural noun with a singular verb; then, God the Holy Spirit introduces Himself in Genesis 1:2; then, the unity of the Triune God is seen collaborating on the creation of the human genome made in their likeness and in their spiritual image as “Our” and “Us;” then, we see the Son introduced in Genesis 3:15 as our Warrior born of the virgin seed of the woman to circumvent the sin-nature of Adam (Romans 5:12) who would do battle with the Serpent, Satan – the Devil (1 John 3:8b; Ezekiel 28:11+) and be victorious; then, Elohim pictures His battle strategy by which the Son would destroy the works of the Devil via selfless love in Genesis 3:21 through the shedding of innocent blood to acquire an imputed robe of righteousness to cover the sin and shame of Adam and Eve (2 Corinthians 5:21) while Elohim rejected the works of Adam to cover his own sin by the works of human hands, self-righteousness e.g. fig leaves (Ephesians 2:8-9) – a Messianic prophecy fulfilled by Messiah Jesus 4000-years later at Golgotha on a Roman Cross with the words “It is finished” (John 19:30).
The Trinity is extant throughout the Scriptures and Jesus is Elohim, our Creator (Genesis 1; John 1; Hebrews 1; Colossians 1) and Jesus is I AM (Exodus 3:14; John 8:58; John 8:24) and if one names the Name of Jesus as Lord and denies His deity as I AM, they remain in their sin and they are therefore headed to Perdition (John 8:24).
When you reject the Trinity, you reject what the Holy Spirit has told you…this is eternal death as only Jesus our I AM could perform the act of redemption through blood atonement as the God-Man, sinless deity, perfection (John 14:6).
Father = Administrator
Son = Creator-Warrior-Messiah-Judge
Holy Spirit – Logistics