The Virgin birth of Jesus, real or unreal has absolutely no bearing on His reality and His teachings. If the Virgin birth made Him special then Adam, without father and mother was twice as special.
He never wrote because His audience were mainly illiterate and His teachings were addressed to the poorest and most down-trodden.
His body was like any human body in that if if disappeared, it did so because it was hidden by His followers.
His resurrection after 3 days means that after His death His disciples began again to teach as they were taught. The reality of Christ was His message, therefore His resurrection was the teaching recommencing after 3 days of mourning.
As for the 4 Gospels, Matthew, Mark, Luke, and John, they are the same story told via different unknown teachers as sermons. The stories differ because they were directed to different audiences. Matthew seems to be speaking to Christians steeped in a Jewish heritage. Jesus gives 5 major speeches to parallel Moses 5 books.
Mark seems to be written for people living outside of Israel and spoke Greek rather than Aramaic and were not too familiar with Jewish customs.
Whomever wrote Luke most likely wrote Acts as well. This is a person who was a companion of or influenced by Paul and was well educated for his time. The Jesus of Luke is stronger and more resolved to His fate.
John is something else altogether. Each Gospel gives of the vibe of what was happening around the writer. When the community faltered, Jesus got stronger and more miraculous in verse.
They are 4 different expressions of the same story with differing embellishments, different audiences that were beginning to mature, different time frames, as such the details tend to be a bit misaligned, but the essence of Christ comes through intact.
There is enough circumstantial evidence to suggest that such a person as Christ existed.
