Is Christianity based on a made-up Jesus?  Or a historical Jesus?  
The early Christian Church actually existed (and was thriving!) well before ANY of the New Testament was written.  The Christian faith exists not because of the Bible, but because of the resurrection of Jesus.
Want to dig into the historical evidence for Jesus outside of the New Testament?  Here are a few videos below.  And if you'd like to read an article by J. Warner Wallace, you can do so here.

​Did Jesus really rise from the dead? 
Is the resurrection of Jesus an historical event? 
What is the evidence?

William Lane Craig writes: 
“There are four facts agreed upon by the majority of scholars who have written on these subjects which any adequate historical hypothesis must account for: Jesus’ entombment by Joseph of Arimathea, the discovery of his empty tomb, his post-mortem appearances, and the origin of the disciples’ belief in his resurrection.
Now the question is: what is the best explanation of these four facts? Most sholars probably remain agnostic about this question. But the Christian can maintain that the hypothesis that best explains these facts is “God raised Jesus from the dead.”

The Apostle Paul wrote: 
And if Christ has not been raised, then our preaching is in vain and your faith is in vain.
-1 Corinthians 15:14

The historicity of the resurrection of Jesus is absolutely essential to the Christian faith. If Jesus was raised from the dead, all the promises of God are true, for Jesus has proven Himself to be the none other than God in the flesh.

If you’d like to read a fascinating article by William Lane Craig, you can find it here.