Paul the apostle witnessed Jesus alive in the famous Damascus Road experience, quite a while after the crucifixion of Jesus. People sometimes witness Jesus alive even today, but do not know as well as Paul did about Jesus dying on the cross. Only a few disciples of Jesus actually saw the crucifixion, and only John went on to write about it as an eyewitness. Paul probably never actually saw Jesus being crucified but he would have known all the facts about it very well because he was a leading figure closely connected to the Pharisees of Jerusalem and met many believers (initially to persecute them) and was a citizen of Rome so he would have good knowledge of everything taking place in Jerusalem, including the crucifixion of Jesus and the stories circulated by the Jews about it, and the resurrection accounts preached by the followers of Jesus. So for Paul to see Jesus alive could mean only one thing to him, that Jesus died on the cross and rose from the dead. He called this his gospel, which he preached fearlessly after seeing Jesus alive, along with the message that salvation is available to all through faith, not just to those who followed Jewish law. Those who preach the gospel today have to rely on the testimony of apostles such as Paul about Jesus dying on the cross and rising from the dead. Even those who witness Jesus alive today in some personal experience of him still rely on testimonies of early apostles who saw him alive and who knew closely the facts about him being crucified and dying. It is therefore vital to the gospel today to preserve scriptures which recorded these things.
