The Model of Christian Charity was the preaching of John Winthrop, a puritan, who focused on how puritanic colonists should act with each other to help each other and the colonies survive. John Winthrop was one of the major leaders in the first Puritan settlement in the USA. What he emphasizes in the sermon is that Puritanism in general acknowledges that the word of God came through the Bible and not through the Church, and that as believers in predestination, people can be good or bad, they can not change the fact whether they are chosen from God or not. Only the chosen ones can hear the word of God and put an alliance with God, which he considered, because God allowed Puritans, as chosen to create a community not only as Christians, but also as Americans. Thus, he thinks that puritans are chosen among people, such as the ancient Israelites chosen among peoples.
Well, Gatsby was deeply lost in his fantasy and illusion that Daisy will come back to him and that they finally will live a very happy life in despite of all the situations that they went through.