As a student of both the natural sciences and philosophy (the latter of which I hope everyone is), I had to figure out what exactly I wanted to find out with my studies. Was it the right arguments to defend my position? Did I want to justify myself? Or did I want to be cool, learn the jargon of physics and philosophy, and impress my friends?
The difficult thing with both of these, is that if done properly, all of these desires are dispelled. One cannot honestly consider issues in science, ethics, epistemology, ontology or indeed theology, and expect to quickly learn how to defend a previously held position. Philosophy, when done right, renews one's mind. Examination of philosophy is the grandest cure for naïvety that the human race has come up with - nothing is left unchallenged. Physics goes even futher. At least it is conceivable that a philosopher remain dogmatic, but the natural world does not care what we think. It simply is. Our notions cannot be left unchallenged.
So what can a truth seeker think when reading the gospel according to St John, the fourteenth chapter? Well, one thing is certain. Such a claim is quite unparalleled in history. Yet it is also rather odd. Scientists vary in exactly how they interpret their work, but one way of thinking of physics is by saying that the equations and concepts developed are our way of understanding what exists.* Here is a man, however, declaring that he himself is the truth. Not something exterior - the fullness of truth in a person. Completely unlike anything I can grasp! The big question of epistemology, "what is true, and what can we, or do we, know?", embodied in a person.
Very well then, if we believe this man (which by now, it should be clear is Jesus of Nazareth), how are we to respond? I can barely grasp what it means for this bloke to be the Truth, but to take a line from the Scottish philosopher David Hume, one cannot deduce an ought from an is. The truth, what exists and is, does not necessarily tell you how things should be, the ought. However, Jesus does not stop there. He claims also to be "the way". The big question of ethics, "how should one live?", answered again by saying that he is the manner one should live. Ridiculous...isn't it?
For some reason, Christians have a tendency to latch on to the last bit - Jesus as a life-giver. This is, of course, crucial, because without this the first two are pointless - but without the first two, the last one is pointless too. Life finds its meaning in truth and the way it ought to be. Jesus says he offers all three.
The Christian response is belief. But everyone has to try and figure out why this man says the things he does. If he is wrong, then who cares? Yet such a striking claim merits consideration. And if he is right, if he speaks the truth, then who could possibly remain unchanged?
* I am an instrumentalist, which essentially means that I think that science discovers the best way of modelling and thinking of phenomena, without necessarily being an objective portrayal of reality as is. Hence, this is not quite my view, but it certainly seems to be the lay-person view and of many of my peers.