"Jesus Only" is False Doctrine

Here's a great link from my bro explaining the heresy of "Oneness" Theology that is plaguing the church, especially the Pentecostal church.

There's one very strong argument that I must add in favor of the doctrine of the Trinity.
I haven't noticed this in any other debate between Trinitarians and the "Jesus only" group, so I figured I'd add this to further the truth.

In John 8:17, Jesus says, "It is also written in your law, that the testimony of two men is true."
His reference is concerning the execution of accused murderers in Numbers 35:30: "Whoso killeth any person, the murderer shall be put to death by the mouth of witnesses: but one witness shall not testify against any person to cause him to die."
Three verses prior in John 8, we read that Jesus is dealing with the validity of His own word. "Jesus answered and said unto them, Though I bear record of myself, yet my record is true: for I know whence I came, and whither I go; but ye cannot tell whence I come, and whither I go."
So then Jesus acknowledges that He is bearing witness of himself. He is one witness to the truth of His doctrine. And in verse 14 He affirms that His record is true.
Now the question must be put forth, how is Christ's record valid according to the law, when it is only he who testifies of it? His doctrine can only be taken as true if another testifies of the same things.
Jesus then justifies his record according to the law in order to establish his own validity by lawful precedent: "And yet if I judge, my judgment is true: for I am not alone, but I and the Father that sent me." and he continues after establishing the truth of the testimony of two men, "I am one that bear witness of myself, and the Father that sent me beareth witness of me."

Oneness theology removes the validity of Christ's Word during his earthly ministry.

The law of testimony in Numbers 35 is grounded in the personhood of the witnesses, as shown by the text. Therefore the separate persons of the Father and the Son are the only means of justifying the words of the Son.
Jesus was not only referring to the testimonial law, but also to the actual testimony of the Father during His earthly ministry: "Then said Jesus unto them, When ye have lifted up the Son of man, then shall ye know that I am he, and that I do nothing of myself; but as my Father hath taught me, I speak these things. And he that sent me is with me: the Father hath not left me alone; for I do always those things that please him."
At the birth of Christ's earthly ministry the Father testified of the Son:
"And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased." (Matt. 3:17)
"And there came a voice from heaven, saying, Thou art my beloved Son, in whom I am well pleased." (Mark 1:11)
Again, the Father testified of the Son at the mount of transfiguration, with the command to hear him:
"While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him." (Matt 17:5)
"And there was a cloud that overshadowed them: and a voice came out of the cloud, saying, This is my beloved Son: hear him." (Mark 9:7)

"The best way to spot a fake, is to get to know the real thing" - Joe Pratt