If Jesus never existed as a historical figure but was only a spiritual symbol, you would expect that there would be evidence of the early church seeing Jesus as ahistorical and then gradually historizing him. But that evidence is not there.
I have spent a lot of time demonstrating that the New Testament presents Jesus as a historical figure. It places Jesus in time and portrays him as interacting with other historical figures who lived within the lifetime of the first readers of the New Testament.
As we we move on into the second and following centuries, we see that these writings also assume a Jesus that existed. Irenaeus discusses the historical Jesus and even debates the age he was during his earthly ministry.
Even Origen, who is known for allegorizing Scripture, explicitly states that an allegorical interpretation does not mean that the historical events did not happen. Origen presumes that the events described in the Gospels actually happened.
From the first century on, we see Christians who are believing that there was an actual Jesus who lived and died and rose again.
If you want to learn more about early Christianity, check out my History of Christianity Podcast website. It has both blog posts and podcast episodes on the history of the church, including the first few centuries.
