It was also his "theology" that led to him supporting the rise of the Roman Catholic Church and to abandon the New Testament format of the church where te local congregations governed themselves and not the Pope from Rome. He wrote many works against "heresies" that were heretical because they did nto want a bishop who sold to to pagan persecution to remain as a pagan and stay in the church. His writings led to very harsh exterminations of those persecutions, including one group was attacked in a crusade.
Luther worked hard to remove much of the power that Augustine had placed in a centralized govenment by putting the Bible in the people's hands. While Luther was only trying to reclaim the Catholic church to a more biblical doctrine, he did realize that the Pope had too much power. Some of that stance can be attributed to Augustine.
Being a "literalist" when taken in an appropriate understanding is the best way to go. Luther orginially coined the method of literal intepretations or sensus literalis. He sought to find Paul's original meaning. You can argue with his results but he is the father of modern textual criticism. Spirituallizing everything leads to how the Catholic Church took power in the Middle Ages. I am not attacking the Catholic Church of today but I want to point out the folly of abandoning true exegetical methods. Augustine was a very shady character in the history of the Church. He contributed much. But the more I have studied church history, the less I like him.