See Acts 9 for Saul’s initial encounter with the Risen Lord. The other Apostles knew Jesus before He was crucified. Jesus appeared to Saul on the Damascus road as the Risen Lord. Saul was surrounded by a light from heaven. He was addressed by name, twice, by the Lord Jesus. He was physically blind and he ate and drank nothing for three days after the encounter. Acts 9:9 “For three days he could not see, and he neither ate nor drank anything.”