As Christians, we take for granted that our faith assumes that Jesus Christ actually existed, as laid out for us in the Gospels, the Book of Acts, and as written by Paul in his letters to the churches. After all, the Church existed in 1st century Palestine, and spread throughout the "world" that time, basically the Roman world. And for centuries, Christians believed that a Jewish historian, Josephus, chronicled not just the beginning of the early Church, but the actual existence of Jesus. His references to Jesus make no mention of Jesus' divinity, in fact, they are mere side-mentions of some other activities happening at that time. Josephus also comments about John the Baptist. We also know that the main Roman personalities mentioned in the Gospels, such as Pontius Pilate, did exist. So, historically, there is good evidence that Jesus did exist.
However, I read something lately that calls some of Josephus' work into question, and whether his writings are accurate, and so therefore, that the person of Jesus found in historical and objective documents actually did not exist.
But for me, I find that when we spend too much time trying to find out whether Jesus existed historically, we end up making far less of a case for His existence. But when we look at the Gospels in the abstract, the "evidence" is far more compelling, and it becomes easier (not the best choice of words) to believe that Jesus did exist. Here are some of those abstract reasons why I believe.
At church today, our lesson was taken from Mark's brief and hurried Gospel. Chapter 1, verse 34, read as follows:
And he healed many who were sick with various diseases, and cast out many demons, and he would not permit the demons to speak, because they knew him.
Our pastor's sermon was titled "Shhh...don't tell", based on this lesson. And for me, this verse, as well as others when Jesus tells His disciples not to tell anyone who he was, is revelatory. Our pastor pointed out that since most Jews expected the Messiah to be a deliverer from Roman bondage and occupation, Jesus, being the Messiah to save us from the bondage of sin, would not be understood too well. So, he's telling them to keep it under their hats, even going so far as telling the demons He cast out from people not to say anything. I find this very compelling because Jesus is focusing the Messianic message on what is really important. I would suggest that if this had been false, or if the person of Jesus was fictional, He actually would or could have been a Messiah to free the Jews from Roman occupation.
That ties into a second event in the Gospels. In Matthew 16:21-23, Jesus outlines His eventual suffering, to which Peter (and I've always thought Peter must've been hated by the others due to his loud mouth and constant "brown-nosing" Jesus) admonishes Christ, saying that it cannot happen, to which Christ says the well-known rebuke "Get behind me, Satan". Again, we have a Messiah not of political freedom, but a Messiah of spiritual freedom.
Finally, another abstract of Christ is the characters themselves. Look at the people surrounding him: the aforementioned brown-nosing and arrogant Simon Peter; the conniving Judas; John, who as Jesus' favorite may have taken advantage of that; Mary Magdalene and her obsessive-compulsive sister Martha, who felt it was better to have the work done than to spend time with Jesus. We see him with lepers, adulterers, prostitutes, even the dead. Jesus does not hang out with the successful - in fact, His tongue is sharpest against what we'd call the establishment. And that speaks to me of the veracity of the Gospels - you could NOT have made it up!
I find that for me, thinking of Jesus in the abstract helps me believe in Him in the concrete. It is the flaws of the Gospels and the individuals that populate them, and the book of Acts, which gives me no doubt in the actual existence of Jesus.
Soli deo Gloria