Understanding Islamic and Christian beliefs and early historical struggles with apostasy, “a kind of disbelief” manifested through action or deed, and martyrdom ameliorates religious discourse between the faiths. Jesuit theologian and progenitor of contemporary Comparative Theology Francis Xavier Clooney celebrated detailed “learning from one or more faith traditions” because the discipline solidifies ecumenical concords across religious boundaries. Clooney opined that Comparative Theology transcends anodyne interreligious observations. Instead, Comparative Theology “is a theological discipline confident about the possibility of being intelligently faithful to tradition even while seeking fresh understanding outside that tradition.” Clooney’s emphasis on interreligious dialogue derived, undoubtedly, from the landmark papal encyclical Nostra Aetate. The Vatican II conciliar document marked a turning point in Church history, recognizing that other faiths “reflect a ray of…[t]ruth which enlightens all.” Nostra Aetate references Islam’s similitudes with Christianity, although recognizing past “quarrels and hostilities” between the two faiths. Alongside some doctrinal similarities, both Islam and Christianity overcame persecutions during their respective nascent years. However, despite these persecutions, both faiths increased their followings, attracting the marginalized, downtrodden, and destitute.