Many times, when I try to quote scripture in reference to what Jesus believed and taught, one of the most common responses I receive from secular individuals is that my argument is to be disregarded because the Bible was written by men. Of course, I don't deny that it was written by men. By that I mean that the Bible was, over the course of time, written not by the hand of an angel but the hands of men like Isaiah, Jeremiah, Matthew, Paul, etc. The big difference between myself and the person of which we are speaking is that I believe in the divine inspiration of scripture, which states that it was through these men that God had written down what He wanted written down.
Yet let us assume, simply for the sake of argument, that these people are correct: that the Bible is not divinely inspired, and Jesus of Nazareth is nothing more than a historical religious figure on par with Mohammad, Guru Nanak, etc. We then run into a grand problem with this Jesus: He seems to be the only historical figure in which we can judge His opinion and teachings separate from what is recorded of them.
What do I mean by this? Well let me explain, and I'll use one of my favorite historical figures - Erwin Rommel. We have Rommel's writings from his war experiences both in World War I and World War II: we have his famous book Infantry Attacks, we have his letters to his wife during the North Africa campaign, and accounts of what he said to his son and staff. Now imagine I made some bold declaration about his opinion on a military matter that could be easily disproved by going to these writings. Someone disproves my argument using those sources, but in response to these citations I simply reply, "Oh, well, I believe that all that were written by men." Yes, they were written by men...but I can't just make up the history of Rommel. I can't reinvent Rommel's attitudes, opinions and actions to fit my personal ideology or beliefs. Anyone who does so is being dishonest.
Some might interject here, "Well yes, but Rommel wrote most of those sources. Jesus didn't write the gospels personally." So we can go to a more fitting example: Socrates. There do not exist any personal writings of Socrates, and most of what we know about what he believed comes from disciples such as Plato. Yet even then, I cannot simply make up what Socrates believed, or reinvent what he would say regarding a certain matter to fit my personal beliefs, at least not without being able to properly demonstrate it. Again, anyone who does so is being dishonest.
Yet of all historical figures, Jesus of Nazareth seems to have the honor of being one of the few in which people can do so. A person can argue for what Jesus believed, and yet when contradicted by scripture simply respond with "Oh, well that's an interpretation," or "Oh, well I don't believe the Bible, that's written by men." The immediate question that must be posed then is: "Very well...from what source then are you getting your opinion regarding the ideology of Jesus?" If they are consistent, they have to admit that they are simply getting it from their own personal opinion and nowhere else. In which case, the God they are worshiping is not the God of the Bible, but themselves. Unfortunately, most who reach this point do not respond in such a manner, and instead respond with emotional arguments.