This is death of Jesus, and at a time in which most women were excluded from participating in public life in Rome, and were considered ritually impure for a substantial portion of their life according to Jewish custom. In this consideration, I think that is why Angel is woman not man. Also,in Luke's book, Jesus appears to the dumbfounded disciples and gives them his last instructions: “in his name to all nations, beginning from Jerusalem. You are witnesses of these things” (24,47–48). Look at this painting, Jesus is kind in the crucifixion, it is like dead but get a new life.