The testimony of the Gospel of Jesus Christ by the early church is recorded in 1 Corinthians 15:1-11.  Taken on its face, it is a masterful, legal presentation of concentric rings of evidence, consisting of different witnesses, with different perspectives, sympathies, indifference, and even opposition, yet who all testified that Jesus is God come in the flesh, who died to take away the sins of the world.  After reading this, no objective person can deny that there is enough evidence to prove the Gospel Message.