John Calvin recognized early on in his Christian life that his gifts and skills were that of a scholar and author rather than an active reformation leader or pastor. Thus, one of the most significant aspects about his life was his ability to systematize protestant theology through writing. His Institutes of the Christian Religion played a major role in the furtherance of protestant theology during the reformation.
Another significant aspect of Calvin’s life was his availability for kingdom ministry. Calvin knew that he was more equipped to be a scholar and author and was reluctant to take on any ministerial roles. In fact, he declined such roles on numerous occasions, but when he experienced the Holy Spirit’s call to certain ministerial work, he submitted and served the church as a pastor. On one such occasion he was on his way to a comfortable life as a writer in Strasbourg, but he was detoured on his trip and landed in Geneva. He had planned on staying in Geneva for a day and then continue on to Strasbourg; however, after he had an encounter with a leader named Farel, who challenged Calvin to stay and pastor those in Geneva, Calvin had a change of heart and decided to stay in Geneva and help the protestant movement. Eventually he left Geneva and made it Strasbourg where he planned on fulfilling his original intentions to settle as a writer, but once again, a leader, named Bucer, recruited Calvin to the pastorate, and Calvin agreed and became the pastor in Strasbourg.
This aspect of Calvin’s life should be emphasized because Calvin could have stuck his heels in the ground and refused to do anything other than scholarly writing, but he had an available heart before the Lord when things were coming together for him to step into pastoral ministry. It was not easy for Calvin to detour from his plan of a quiet life as a writer, but I imagine that he recognized that God was leading him in different directions, and so he needed to follow God rather than pursue his own ambitious plans.
 Justo L.González, The Story of Christianity: Vol.2 Reformation to the Present Day, Rev. and Updated, 2nd ed. (New York: HarperOne, 2010), EPUB edition, pt. 1, ch. 7, “The Reformer of Geneva.”