At John 20:24-27 (NRSVCE) we see:
But Thomas (who was called the Twin), one of the twelve, was not with them when Jesus came. So the other disciples told him, “We have seen the Lord.” But he said to them, “Unless I see the mark of the nails in his hands, and put my finger in the mark of the nails and my hand in his side, I will not believe.
A week later his disciples were again in the house, and Thomas was with them. Although the doors were shut, Jesus came and stood among them and said, “Peace be with you.” Then he said to Thomas, “Put your finger here and see my hands. Reach out your hand and put it in my side. Do not doubt but believe.”
My question is: Why was it necessary for Jesus to retain the wounds he had received at the cross, even after His glorious resurrection? Was it done to convince the disciples that it was Jesus Himself appearing before them, or was it a symbolic statement that Jesus continues to suffer for the sins of mankind? What do the teachings of Catholic Church say about the post-resurrection wound marks of Jesus?