Even if you don't believe that Jesus was the Son of God, there are many proofs that He was a real person
who walked the face of the Earth.
First, there is the existence of Christianity itself. To believe that Christianity sprung up around someone
who never existed stretches the limits of imagination. There is no major religion in existence in which the
founder actually never existed.
Second, even outside the Bible, there are numerous references to Jesus that indicate He was a real person. In the first century, a Roman historian named Tacitus wrote about Jesus suffering under Pontius Pilate. The Jewish historian Josephus mentions Jesus in his writings from 93 A.D., which was approximately 60 years after the time that Jesus was crucified by Pilate. Suetonius, who was the chief secretary to Emperor Hadrian wrote of a man named Chrestus (or Christ) who lived during the first century.
But perhaps most important of all, there were many eyewitnesses to the life, death, and resurrection of Jesus. In the four gospels, we encounter many different people who had their lives totally transformed by Jesus. He was publicly crucified in front of hundreds of people. And when He rose from the dead, He was seen multiple times by different groups of people, including a group as large as 500.
So yes, there is a large amount of evidence that Jesus was real. But beyond that, there is significant proof that He truly was the Son of God.