The Truth about what?   God.   

That is a blasphemous claim unless He in fact is God - which He is!   

But there were false prophets also among the people, even as there shall be false teachers among you, who privily shall bring in damnable heresies, even denying the Lord that bought them, and bring upon themselves swift destruction. 2Pe 2:1 To believe in Christ Jesus is to become a Child Of The Holy Spirit.      To reject Christ Jesus is to be a Child Of Satan.      To be a Child Of The Holy Spirit is to experience Eternal Life.      To be be a Child Of Satan is to be condemned to Eternal Death.      Denying the Lord Jesus Christ can be done in different ways.     Every way boils down to denying Him as Mighty God and Everlasting Father.      Jesus is the express image of that which we call 'God'.      Jesus is the Spirit Soul And Body of our Creator.     Any other theology that calls itself by the name Christian has adopted Damnable Heresies.

We can differ on many subtle aspects of Christianity and still be in fellowship with the Holy Spirit Father of Christ Jesus.   

But, we cannot come to the Holy Spirit Father except through Christ Jesus.   

What does `through Christ Jesus` mean?   
   → It means that we accept the Words of Jesus Christ about Himself.   
   → It means we accept the Words of prophecy from the Old Testament about the Messiah.   
   → It means we believe that Jesus is the Mighty God, the Everlasting Father, the Saviour, the King, the Lord of all

The Jews of Jesus day rejected Him as Mighty God.   

Early Christians, influenced by Judaism found it difficult to turn lose of YHVH in favor of Jesus.   So, the insidious concept of the trinity took shape.   In their thinking
   → not only was Jesus divine but
   → YHVH continued to exist as a separate person from Jesus, furthermore,
   → when the Holy Spirit was poured out, they created a 3rd person and,
   → though Jesus was born of the Holy Spirit, the Holy Spirit was relegated to person 3rd class in the trinity,
   → this in the face of Jesus saying that He and His Father are one and
   → that He is the express image of His Father.   

So, this unseen, unexperience being to whom Jesus and the Holy Spirit are accountable came into theological existence.   

All of this theological wrangling served only to derail the power of Christianity which is Christ Jesus the personification of His Holy Spirit Father.   

How Christ Jesus will deal with believers who doubt His Almighty status is up to Him.   However, it is abundantly apparent from the weakness in the church that this damnable heresy is the root cause of this weakness.   

Jesus is the name of `God`.   Not acknowledging this is damnable because
   → it denigrates the name of Jesus
   → it elevates another being to authority over Jesus
   → it undercuts one`s fellowship with the Holy Spirit Father
   → it therefore cuts one off from Grace that is through faith In Christ Jesus

One cannot believe In Christ Jesus and not believe what He said about Himself Mat 28:18.    Hence, those who deny the Almighty status of Christ Jesus are effectively denying the person of Christ Jesus.   

Obviously teaching and believing that one can be saved in the name of Jesus while doubting Jesus` integrity is a damnable heresy.   

Here are some of the forms of this heresy:
   → Jesus is just the Son Of God
   → Jesus is the emissary of God for salvation
   → Jesus is a great prophet
   → Jesus is just a human used by God
   → God can save people as well as Jesus
   → People can be saved without going through Jesus

Either Jesus is Lord of all or He is not Lord at all.