Rebuild My Church is the first critical analysis of the development of the thought of Fr. Peter Damian Fehlner, a Franciscan theologian for whom the work of Christ always moves forward, never backward. The definitive study of Fehlner's explicitation of the thought of St. Bonaventure, Bl. John Duns Scotus, St. John Henry Newman, and St. Maximilian Kolbe within the constitution of modernity construed both positively as a reason to cheer and negatively as a reason to weep. A middle view watches for developments. Interpretation is the question of questions. When did Christianity become modern and at what price? At Vatican II, engagement with modernity began in earnest for the first time with the Catholic Church's irrevocable goal to build a "bridge" to modernity. As the Council intended, Fehlner critically engaged Kantian, Hegelian-Marxist, and Heideggerian inspired thought that seeks to repackage Christianity. Fehlner replied to the complex truth and phenomena thrown up by history. Vatican II asked what to take on board from modern life when the context of the believer and history have changed. If we forget the essential elements, will we remember what Christianity was and is? Fehlner is a new embodiment of Bonaventure, Duns Scotus, Kolbe, and Newman. Fehlner discovered an incalculable resource for the renewal of theology in the dialogue between Newman and Duns Scotus, and its relation to Vatican II. The starting point is God's call to St. Francis: "Rebuild My Church." Like Francis, Fehlner recognized Mary, Mother of God as the "Virgin made Church."