We're the hardships endured by the mariner necessary for his complete change? Why? Why not?

The Mariner begins to discover that killing the albatross was a mortal sin. The ship remains stranded at sea with no wind to move them. The Mariner is angry at his fate and curses the sea and creatures in it. The men on the ship begin to die one at a time until the Mariner finds himself alone. The Mariner suffers for seven days in thirst and hunger. The Mariner must suffer to understand his sins as well as his place in the natural world. It is not until he is near dead when he sees the beauty of the universe and God's creatures. The sea snakes become beautiful to him and the Mariner finally has a change of heart and spirit.