This changes John 3:16. Now I had to believe that God the father so loved the world that he sent his son who is also himself, and whosoever believes that he sent his son who is also himself will not perish but have eternal life.
The trinity solves the central problem of Jesus: if Jesus claimed, in font of the Jews, to be God, they would have stoned him on the spot; thus proving he was not God, because God can't be killed. (Or, what type of God stands there, and lets you stone him?)
Jesus (the man) had to claim to be something vague, like the "Son on Man". This was then scripturally upgraded to "Son of God", and then actually God, after he was dead, when nobody could kill him, because he was already dead.
There is no way to put Jesus saying "I am God" into the gospel, without wondering why any crowds he preached to, didn't immediately stone him.
The early accounts of Jesus, in front of Sanhedrin, Pilate and Herod, obviously have him denying divinity, because he didn't think he was divine, or preaching against Judaism, so he didn't want to be martyred.
John, which is the gospel most likely to upgrade Jesus, still has to stick to this mortal narrative, or people will smell a rat. What would be wrong with Jesus claiming to be God in front of Pilate, or the Sanhedrin? The book of John says he deliberately sent Satan into Judas, to turbo charge him. Then he gets in front of the rulers and tries to evade being punished, by keeping quiet. What would have been so bad, to stand in front of the Sanhedrin, and say, "OK, the gig is up. I am actually God. You caught me"?
To make Jesus work, you have to hide his divinity. This works so well, that liberal Christians are brought up believing that Jesus was a profound and worthy teacher, who was martyred. I managed to get through a Church Private school in Australia, without figuring that Jesus was supposed to actually be God. I managed to twig to the fact that some people around me actually believed that Jesus did miracles and resurrected. But I never figured that (a) people believed Jesus was God, (b) people believed his resurrection did anything besides prove that Jesus wasn't lying.
The texts have to be structured in a way that only reveals to the audience that Jesus is God. The Trinity makes the whole thing vague, so "Jesus" can hide, when asked strategic questions.