Not only does Jesus characterize Himself as truth in John 14:6, but He also adds in John 17:17 that "[God's] word is truth." In I Corinthians 15:45, 47, Paul refers to Jesus as "the last Adam" or "the second Man," the beginning of a new order, of an entire race or family of beings just like Him, just as all of mankind is in the image of our first forefather, the first Adam.
Many can say, "I have told you the truth." However, Jesus did not just tell the truth, He embodied it. He put truth into a visible, concrete form so all who so desire can see it. What credibility that gives! A teacher can present a mathematical, grammatical, scientific, or historical truth, and what kind of a person he is does not matter much. However, if a person teaches or administers moral truth, his example—what he is in his character—is all-important. Do people want to be lectured on purity by an adulterer or on honesty by a liar and thief (Romans 2:21-24)?
"Truth" in John 17:17 is the Greek word aletheia, which means "reality, the manifested, unconcealed essence of a matter." Truth is the reality lying at the foundation of a righteous example. It is pure unadulterated reality.
You are of your father the devil, and the desires of your father you want to do. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he speaks a lie, he speaks from his own resources, for he is a liar and the father of it.
Satan is Christ's diametrical opposite, one hundred percent unmodified deceit. God's entire plan is based on the premise that the converted know that God is true. If He is not true to His Word or to His own way of life, how can He be trusted? We must live by faith in this true Being and in what He says! Truth forms the basis, the foundation, the reality, for a person's conversion.
Consider this: There is a personal, living, almighty God whose ways and laws are intrinsically right—they are true. Therefore, a person who has God's Spirit and is honest, who is willing to speak the truth and acknowledge it when it is shown to him, and who will use it in everyday, practical situations must eventually become like the One he models himself after.
God is making us kings and priests, that is, leaders and teachers of a way of life based on revealed truth. He will not have anyone in His Family who does not embody truth as Jesus did. In other words, we, too, will be truth personified. However, for this to occur we must live it to the best of our abilities now.