This is just about the most profound part of the verse. Jesus says that after the way, he is the truth. What makes this so bizarre is to compare it with philosophy. In an intro class I have taken at college, one thing that stuck with me was the pursuit for truth. This search is right next to man's search for life beyond this planet, or the meaning of life, or even what came first: the chicken or the egg? Good questions nonetheless, but the question about absolute truth effects the conclusions to all those questions. For if we do not find out what truth is, our conclusions could just be the opposite of what it really is. So many man hours have gone into defining truth, but more so searching for it. It is even believed that everything is just a cover up and we can never find true truth.
Jesus on the other hand knows the truth. In fact he knows it real well. In fact, he is the truth! All of the searching by man can come to an end, for the conclusion is as simple as saying that it is one man. Though only part man, Jesus proclaimed himself as truth because he is also part God. Yet man keeps searching for the truth because he has reason to be suspicious of what he already knows. Man cant accept that the Earth is in the center of the universe, so he keeps pushing on to where he discovers we aren't even in the center of our solar system! He keeps pushing to discover that there is another half of the world, that its not just an age old rumor (because Columbus just made it official, others were going to the New World for what is now believed to be thousands of years previous to 1492).
But this is all physical truth. When Jesus said he was the truth, he already knew that the sun was in the center of the solar system, and he even knew all the hairs on the head of a Native American living in present day Mexico. But his message was not to give wordly knowledge, for that can be obtained by us by ourselves. All that we are doing is finding out the code to God's physical creation. God's knowledge about his spiritual creation though is only obtainable through Christ and all the others who God has chosen along the way (as in the Jews; Abraham, Paul, ect). Christ is the only WAY (see my previous post) to God's spiritual creation. The way to get there is by listening to and obeying the truth. Only when we believe (which its definition is accepting as the truth, very fitting and ironic) that Jesus is truth, then we can begin to be the new creation that God wants us to become.
Jesus is TRUTH and this is what we have to accept in order to enter the narrow gate
(Matthew 7:13-14). This narrow gate is narrow, because there are many different ways to the god or gods due to all the different religions. But There is only one true God, and his Son is the way to him, the truth about him, and...........