Explain why someone in heaven must die for man. Who volunteers for this mission and why?

God answers that a suitable sacrifice must be made: someone worthy must offer to die to pay for man’s sin. The angelic choirs are silent, but the Son immediately offers himself. He will become mortal so that God can yield to Death and conquer Hell. God is overjoyed, even though he will be giving up his son, because he knows that it is good to sacrifice his son for the salvation of the human race, in order for justice and mercy to be served. Those that have faith in the Son will be redeemed, but those who do not accept grace will still be doomed to Hell. The choirs of angels now break into a song of praise extolling the goodness of both Father and Son, which will turn a sorrowful deed into greater glory for both God and man.