On Friday afternoon, Bishop Hicks, once the leader of a suburban diocese near Chicago of roughly half a million people, will become one of the most prominent religious figures in the country, representing New York’s more than 2.5 million Catholics. But despite the grandeur of the ceremony and the gravity of his new title, the bishop on Thursday aimed to keep the focus on what he saw as the spiritual responsibilities of his position and the role that the church will play in helping him fulfill them.