Why is the Trinity essential to Christianity?

We do not have to fully understand it to accept it:

"Einstein said he didn’t understand electricity. He said he hoped before he died he could understand electricity And he never did. Vance Havner added, 'I don’t understand it either, but I’m not going to sit in the dark until I do...'” Full text: God in Three Persons, Blessed Trinity by Adrian Rogers

The doctrine of the trinity is proved from scripture (Mt 3:16,17; 28:19; Ro 8:9; 1Co 12:3-6; 2 Co 13:14; Eph 4:4-6; 1Pe 1:2; Jude 1:20,21; Re 1:4,5).  Divine titles are applied to the three persons in the trinity (Ex 20:2; Jn 20:28; Ac 5:3,4).

Response to comment [from a "Christian"]:  "God is plural."

God is one (Deut 6:4).  One what.  Three whos (Mt 3:16,17; 28:19; Ro 8:9; 1Co 12:3-6; 2 Co 13:14; Eph 4:4-6; 1Pe 1:2; Jude 1:20,21; Re 1:4,5, Ex 20:2; Jn 20:28; Ac 5:3,4).

Response to comment [from a Christian]:  [Nature of God]

Response to comment [from a Christian]:  "None of us inherit a sin nature. A sin nature forms as we sin (moral/volitional). It is not genetic, innate (metaphysical)."

What part of creation was not corrupted by Adam's sin?  Ro 8:21.

"He [Jesus] is sinless because He never sinned..."

Could he have sinned?

[Could Jesus have sinned?]  "I believe He could have, but did not."

How can a holy (Ex 15:11; 1 Sa 2:2, Ps 22:3; Jn 17:11) and perfect God (Deut. 32:4; 2 Sam. 22:31 Psa. 18:30. Matt. 5:48; Rom. 12:2; Jas. 1:17) sin?  You do not describe the God of scripture (1 Jn 4:3; 2 Jn 1:7, Heb 4:15).

"Moral depravity also affects all of us, except Christ..."

Why?

Response to comment [from a Christian]:  "...[W]ill not is not cannot. God always lives holy, loving, intelligently, unlike His creation....[F]orget about marginalization with false accusations of denying God, Bible, gospel....It is galling when your view is flawed to accuse more correct views of having a different god instead of just a different view on the same God. Get it?"

God is committed to righteousness.  It is part of his character (Ps 7:9; 116:5; 119:137). 

Response to comment [from a Christian]:  "...[C]haracter is what we do with our being, but it is not being...Get over it..."

Take it up with David--God is righteous (Ps 7:9). 

"...God is loving, holy, just, merciful, etc. because He is personal and moral, not because He is uncreated triune spirit nature..."

Strawman.  I am not speaking about his triune nature.  I am speaking about his holiness, perfection, and righteousness.

"Lucifer had spirit nature and was righteous, but then he used his will and mind in pride and became fallen..."

Why do you compare an uncreated being to a created being?  Is God like Satan?  Ex 9:14; De 33:26; 2Sa 7:22; Isa 46:5,9; Jer 10:6.

"Thomas Aquinas and Augustine are wrong..."

Stawman.   I reject both.

Response to comment [from a Christian]:  [Is the temptation of Jesus possible?] "You are correct, Serpentdove...God cannot even be tempted with sin; must less have the ability TO sin:  James 1:13 Let no man say when he is tempted, I am tempted of God: for God cannot be tempted with evil, neither tempteth he any man."

Do you think Jesus could have fallen into sin?  James 1:13.  As a reminder, Keypurr is number one on Satan Inc (TOL Heretics List ).

"If He could have sinned, He would still be able to sin today because He retains the same essence He did while living on earth. He is the God-Man and will forever remain so, having full deity and full humanity so united in one person as to be indivisible. To believe that Jesus could sin is to believe that God could sin. 'For God was pleased to have all his fullness dwell in him' (Colossians 1:19). Colossians 2:9 adds, 'For in Christ all the fullness of the Deity lives in bodily form.'

Although Jesus is fully human, He was not born with the same sinful nature that we are born with..." Could Jesus have sinned (peccability or impeccability)?

Response to comment [from a Christian]:  "God is righteous, but why is He? Because He is spirit or because He chooses it?  I Peter 1:13-16 morals/volition, not metaphysics (cf. Rom. 6;13-16).  Aquinas was wrong on his 'being' speculations, a confusion of categories (philosophical issue of morals vs metaphysics). The danger with your view is that it leads to homosexuals thinking they are born that way (innate vs chosen)."

What part of God could have sinned?  1 John 3:5. 

The Creator is separate from his creation (Ge 1:27).  God is free from guilt (Jn 8:46) or defilement (Heb. 7:26, 27). 

"God has will..."

Red herring. Who has argued that God does not have a will?

"He is not robot."

Red herring. Who has argued that God is a robot?

Desires in the human heart are evil (Mt 15:19).  An evil desire occurs when a soul believes that a sin can fulfill him/her.  When did Jesus believe that a sin would fulfill? If he was thirsty, he desired water.  If he was hungry, he desired food.  When did he desire sin? 

What does Immanuel mean to you? Mt 1:23, Jn 1:1-3

"The verse affirms that God is holy, sinless, we agree."

What do you mean by "God"? Jn 1:1-3. Who is being described here:

And God said to Moses, “I AM WHO I AM.” And He said, “Thus you shall say to the children of Israel, ‘I AM has sent me to you.’ ” Moreover God said to Moses, “Thus you shall say to the children of Israel: ‘The Lord God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, has sent me to you. This is My name forever, and this is My memorial to all generations.’ Go and gather the elders of Israel together, and say to them, ‘The Lord God of your fathers, the God of Abraham, of Isaac, and of Jacob, appeared to me, saying, “I have surely visited you and seen what is done to you in Egypt (Ex 3:14-16).

"...No one disputes God's perfection and holiness..."

What do you mean by "God"? Jn 1:1-3. We trust in the character of God's Son. You talk a lot about how he could have sinned but you fail to talk about his holiness (Ps 16:10, Is. 11:4, 5).

He came to destroy sin and death (Jn 1:29; 1 Jn 3:5). How could he destroy sin if he had a problem with it himself? 2 Co 5:21; Heb 4:15; 7:26; 1 Jn 3:5.

You are the spot and blemish (2 Pet. 2:13). The Lord is without spot or blemish (Eph. 5:27).

Was he 100% man and 100% God?

Explain what Son of Man means (Gen. 3:15; Deut. 18:15–19; Psa. 22:22; Isa. 8:18; Isa. 9:6; Dan. 7:13; Matt. 16:27, 28; Matt. 18:11; Matt. 20:28, 30, 31; Matt. 21:9; Matt. 26:2, 26–28, 36–45 Mark 14:34, 42. Matt. 26:64; Mark 2:28; Mark 9:9, 12; Mark 10:33, 45; Mark 14:21, 62; Luke 2:11–14; Luke 5:24; Luke 17:22, 24; Luke 18:31; Luke 19:10; Luke 21:36; Luke 22:48, 69; John 1:14; John 5:27; John 12:34; John 13:31; Acts 7:56; Acts 17:31; Gal. 4:4; Phil. 2:7, 8; 1 Tim. 2:5; Heb. 2:9, 10, 14–18; Heb. 10:12; 1 John 4:2, 3; 2 John 7; Rev. 1:13; Rev. 14:14).

Explain what Son of God means (Psa. 2:7; Psa. 89:26, 27; Matt. 3:17 Mark 1:11; Luke 3:22. Matt. 4:3, 6; Matt. 10:40; Matt. 11:27 Luke 10:22. Matt. 14:33; Matt. 15:13; Matt. 16:15–17; Matt. 17:5 Mark 9:7; Luke 9:35; 2 Pet. 1:17. Matt. 18:10, 19; Matt. 20:23; Matt. 21:37 Luke 20:13. Matt. 26:53, 63, 64; Matt. 27:43, 54; Mark 1:1; Mark 3:11; Mark 5:7 Luke 8:28. Mark 14:61, 62; Mark 15:39; Luke 1:32, 35; Luke 4:3, 9, 41; Luke 9:35; Luke 10:22; Luke 22:29, 70 Mark 14:61. John 1:1, 2, 14, 18, 34, 49, 50; John 3:16–18, 34–36; John 5:19–21, 23, 26, 27, 30, 32, 36, 37; John 6:27, 38, 40, 46, 57, 69; John 7:16, 28, 29; John 8:16, 19, 26–29, 38, 40, 42, 49, 54; John 9:35–37; John 10:15, 17, 18, 29, 30, 36–38; John 11:4, 27, 41; John 12:49, 50; John 13:3; John 14:7, 9–11, 13, 16, 20, 24, 28, 31; John 15:1, 8–10, 23, 24; John 16:5, 15, 27, 28, 32; John 17:1 vs. 1–26.; John 19:7; John 20:17, 21, 31; Acts 3:13; Acts 13:33; Rom. 1:3, 4, 9; Rom. 8:3, 29, 32; 1 Cor. 1:9; 1 Cor. 15:24, 27, 28; 2 Cor. 1:3, 19; Gal. 1:16; Gal. 4:4; Eph. 1:3; Eph. 3:14; Col. 1:3, 15, 19; Col. 3:17; 1 Thess. 1:10; Heb. 1:1–3, 5; Heb. 4:14; Heb. 5:5, 8, 10; Heb. 6:6; Heb. 7:3; Heb. 10:29; 1 John 1:7; 1 John 2:22–24; 1 John 3:8, 23; 1 John 4:9, 10, 14; 1 John 5:5, 9, 10, 13, 20; 2 John 3; Rev. 2:18).

What percentage of Son of Man was he. What percentage of Son of God was he? Jn 1:1-3.

Why is the Trinity essential to Christianity?