John Piper lists 9 Ways to Know the Gospel of Christ Is True @ www.desiringgod.org.
Brief explanations follow the points:
1. Jesus Christ, as he is presented to us in the New Testament, and as he stands forth from all its writings, is too single and too great to have been invented so uniformly by all these writers.
2. Nobody has ever explained the empty tomb of Jesus in the hostile environment of Jerusalem where the enemies of Jesus would have given anything to produce the corpse, but could not.
3. Cynical opponents of Christianity abounded where claims were made that many eyewitnesses were available to consult concerning the resurrection of Jesus from the dead.
4. The early church was an indomitable force of faith and love and sacrifice on the basis of the reality of Jesus Christ.
5. The prophesies of the Old Testament find stunning fulfillment in the history of Jesus Christ.
6. The witnesses to Jesus Christ who wrote the New Testament gospels and letters are not gullible or deceitful or demented.
7. The worldview that emerges from the writings of the New Testament makes more sense out of more reality than any other worldview.
8. When one sees Christ as he is portrayed truly in the gospel, there shines forth a spiritual light that is a self-authenticating.
9. When we see and believe the glory of God in the gospel, the Holy Spirit is given to us so that the love of God might be "poured out in our hearts" (Romans 5:5).