The Trinity doctrine is a major or foundational doctrine for many Christians, so how could it be wrong?

Well history shows us that many Christians have been wrong in the past, the Reformation of the sixteenth century is one proof of this. Martin Luther pointed out that many of the so-called churches doctrines were false and he set out to to show the truth from scripture instead. Some of Martin Luther's doctrinal corrections included matters that covered faith, salvation, baptisms and many other important subjects. In fact, Luther questioned 95 main points in his thesis, all aimed at the oppressive doctrine of the Roman Church. Of course Luther was anything but perfect himself, but he did challenge some things that needed challenging and the result of this was that some truths were restored back to the Church of God. However, Martin Luther may have preached truth on many subjects pertaining to the Church, but he still preached the Trinity doctrine and held to this false foundation. So yes Martin Luther like all of us, was not perfect, but God rarely works through one man (except Christ) rather he works through his Church to reveal his truth..

However, as a result of the Reformation that Martin Luther sparked, Christians today freely acknowledge that salvation is a free gift of God and not by works, and many Christians know that we are not required to pay penance. Yet there was a time when salvation came by works and penance was preached, but today we know better.

So what makes us think that we have all the truth today. What gives us the false idea that denominational teachings are beyond question and the foundations of these denominations (creeds) are set forever. As it is written in Ephesians 5:27
That he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish.

So it is clear that our bridegroom is coming back for a bride without blemish. Who are we to think that we are without blemish today? We must realize what Philippians 1:6 is saying:
being confident of this, that he who began a good work in you will carry it on to completion until the day of Christ Jesus.

So we are clearly in a state of change, a state of being perfected. Our wrinkles are being ironed out, our spot and blemishes are being removed and we are being transformed from darkness into God's glorious light. So yes it is very possible that there maybe some major errors in what we believe and not only does history teach us that this is possible, but scripture warns us of it as well.

2 Thessalonians 2:3
3 Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;

Acts 20:29-31
29 I know that after I leave, savage wolves will come in among you and will not spare the flock.
30 Even from your own number men will arise and distort the truth in order to draw away disciples after them.
31 Therefore watch, and remember, that by the space of three years I ceased not to warn every one night and day with tears.

So yes, Paul even teaches that there will be a great falling away. This will happen before that great day of Christ's return. The falling away being spoken of here is taken from the Greek word 'Apostasy'.

apostasia {ap-os-tas-ee'-ah}
to forsake, falling away, a falling away, defection, apostasy
feminine version of the word apostasion.

Apostasion: divorce, repudiation, a bill of divorce .

So the Apostasy/great falling away/divorce is talking about a departing from Christ and we know that Christ is the truth, so a falling away would involve a departure of the doctrine of Christ. After this happens, the Man of Lawlessness is revealed as he is the fulfillment of mans lawlessness. Following that, the great gathering of the faithful to Christ will take place.

Apostasy > Antichrist > Jesus Christ.

So yes, it is not only possible that there will be great deception and a falling away from truth, but it is inevitable. So it shouldn't be that much of a shock to find that the Trinity doctrine is a false foundation, so why should we continue to believe it. Why should it remain as the foundation of our faith, when the foundation of true faith is that truth that Jesus is the Christ and the Son of God.

Matthew 16:13-17
13 When Jesus came to the region of Caesarea Philippi, he asked his disciples,
"Who do people say the Son of Man is?"
14 They replied, "Some say John the Baptist; others say Elijah; and still others, Jeremiah or one of the prophets."
15 "But what about you?" he asked. "Who do you say I am?"
16 Simon Peter answered, "You are the Christ, the Son of the living God."
17 Jesus replied, "Blessed are you, Simon son of Jonah, for this was not revealed to you by man, but by my Father in heaven.
18 And I tell you that you are Peter, and on this rock I will build my church, and the gates of Hades will not overcome it.

We (God's children) are even told in Revelation to come out of Babylon and we know that Babylon was a city that God destroyed because of her idolatry and false religion. Even though she was destroyed her influenced lived on and she made the whole world drunk on her wine. We are warned to not to be influenced by her in Revelation 18:4
Then I heard another voice from heaven say: "Come out of her, my people, so that you will not share in her sins, so that you will not receive any of her plagues;

So if the scriptures quoted thus far, clearly demonstrate to you that Jesus is not the Most High God, rather his son, then you would do well to believe the truth in scripture and keep away from the wisdom of man and man made teachings and creeds. As it is written in 1 Corinthians 1:20
Where is the wise man? Where is the scholar? Where is the philosopher of this age? Has not God made foolish the wisdom of the world?

I encourage all toward a living relationship with God and to be led by his Spirit and to change when he shows you truth. If you resist and continue to follow the words of men, then what reward will you receive for following the words of men over the truth of God? Do you fear God or Man? Are we not recognized by the fact that we are lead by the Spirit and have crucified the flesh. Are we not recognized by the fact that we should be lead by the Spirit of God and not the mind of man. As it is written in Romans 8:14 because those who are led by the Spirit of God are sons of God.

It is also written in 1 John 4:2
This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God,

and 2 John 1:7
Many deceivers, who do not acknowledge Jesus Christ as coming in the flesh, have gone out into the world. Any such person is the deceiver and the antichrist.

So why is it that Trinitarians teach that God came in the flesh and that we must believe that Jesus is God or we are of the antichrist. Are not such teachings false? This Trinity doctrine teaches us that God is triune, not one as scripture says. This false doctrine teaches us that God came in the flesh and it teaches us that God became a man and that God died and God took sin on himself. This is not only false, but it is truly stupid. You would do very well to keep away from this false teaching. Instead we should heed the words of the following scripture:

John 14:1
"Do not let your hearts be troubled. Trust in God; trust also in me.