This article begins by recalling the path that Catholic and Lutheran theological and historical research has taken over the last century to liberate the image of Martin Luther from one-sided interpretations and distortions. The dialogue between the two churches demonstrates how much Luther and his theology are rooted in the great tradition of the church, although his approach differs somewhat from that of scholastic theology, especially late scholasticism. This way of proceeding proved ultimately fruitful in the Joint Declaration on the Doctrine of Justification, ratified by the Lutheran World Federation and the Roman Catholic Church on October 31, 1999. The article then explains how the document From Conflict to Communion, achieved through the same historical-critical- hermeneutic method, has addressed four topics that traditionally have been in dispute: first, the relationship of grace/ freedom and faith/works in justification and sanctification; second, the real presence of Christ in the Eucharist and the sacrifice of the Mass; third, the divine origin of the ordained ministry and its relationship to the common priesthood of all the faithful; and fourth, the relationship among scripture, tradition, and the magisterium. Beginning from these insights, the document shows how the different doctrinal emphases of Lutherans and Catholics, freed from polemical emphases, should not be mutually exclusive and therefore should not preclude consensus on fundamental truths. Giving birth to a different church was not Luther’s original intent. Hence it can be argued that in these days the condemnations against Martin Luther ought to be re-examined, making the figure of Luther available to being discovered beyond the regrettable historical events. Here we find his true ecclesiology and ultimately his “Catholicity.