To my way of thinking, you simply cannot be a Christian without believing in the historicity of Jesus Christ. In fact, the standard is well above historicity but more on that later. Strangely, some liberal mainline churches disagree. The fact that it needs to be addressed is not disputed, albeit a sad circumstance. I suppose their doubt spawns from the murky waters of a post modern culture that views truth as relative and vacuous. Yet to call one’s self a Christian without believing in a real man named Jesus of Nazareth, that walked the shores of Galilee, is like Don Quixote tilting at windmills. It is absurd.
The unanimously accepted historical facts really don’t make any sense without Jesus. The purpose of the BC / AD dating system was to make the birth of Jesus Christ the dividing point of world history. Why would that be the case, apart from a real man making a huge impact? The early Christian church started in Jerusalem amongst the Jews. If you go to Israel you will discover that the Sabbath is still taken very seriously today. The elevators stop on every floor because pushing the button is considered work. How can you explain the fact that so many pious Jews abandoned the Saturday Sabbath for Sunday worship apart from a belief that Jesus rose on Sunday? How could you possibly account for the rapid rise of the Christian church amongst ferocious Roman and Jewish persecution apart from the fact that a really important man named Jesus of Nazareth actually lived? And how do you explain all the willing martyrs? Why would anyone die or withstand torture for a myth? Considering his impact on history, at the bare minimum don’t you think there must have been a real man named Jesus of Nazareth?
The accounts in the Bible are powerful evidence he existed even if you don’t accept the claims of miracles. For instance, critical scholars widely agree that Paul’s letters were written very close to the time that Jesus lived. Let’s talk about 1 Corinthians which is dated at A.D. 55/56. In that letter Paul uses a preexistent creed that claims over 500 eyewitnesses to the resurrected Jesus and dates back, some scholars date say to within two years of Jesus death. Dr Habermas maintains that “Critics not only admit this data, but were the first ones to recognize the early date.” In addition, there are many secular sources that discuss Jesus as a historical figure. For example, the Roman historian Cornelius Tacitus (ca. AD 55-120) wrote in his work the Annals,
Consequently, to get rid of the report, Nero fastened the guilt and inflicted the most exquisite tortures on a class hated for their abominations, called Christians by the populace. Christus, from whom the name had its origin, suffered the extreme penalty during the reign of Tiberius at the hands of one of our procurators, Pontius Pilatus, 
So you can see that he readily acknowledges the historicity of Jesus and his crucifixion by the Roman procurator Pontius Pilot just like the Gospels maintain. Even the Jewish historian Josephus acknowledges that Jesus lived and had a following. I’m only scratching the surface perhaps take a look at the book The Case for Christ.
Despite the assertions of the neo atheists faith is not belief without evidence. Faith is firmly based on evidence. For instance, a husband has faith in his wife because he knows her track record and character from real space time history. With this faith in tow, when he sees her in a conversation with a strange man he does not feel jealous because of this well founded faith. However, if his wife had a track record of infidelity this faith would be misplaced indeed. If Jesus of Nazareth was not a true historical figure the Christian faith is likewise misplaced.
Christianity is better understood as a relationship than religion, a relationship with a real risen Lord. Christians not only affirm historicity, they maintain that Jesus is God incarnate. Our faith is evidenced by a real historical event, the resurrection. Jesus rose from the dead and authenticated his ministry for all time. No other religion has such a claim. The Apostle Paul affirmed this clearly back in the first century, “And if Christ has not been raised, then our preaching is in vain and your faith is in vain.” (1 Co 15:14, ESV) Thus apart from affirming the historicity of Christ and his resurrection, you cannot be called, in any meaningful way, a Christian.
 Myers, Allen C. The Eerdmans Bible Dictionary. Grand Rapids, MI: Eerdmans, 1987.p. 58
 Strobel, Lee. The Case For Christ. Grand Rapids MH: Zondervan, 1998. p.213.
 Ibid. p.30.
 Habermas, Gary R. The Historical Jesus: Ancient Evidence for the Life of Christ. Joplin,MO: College Press Publishing Company, 1996.p.30.
 Ibid. p.188.
 Ibid. p.192.