Following the Age of Enlightenment, the French and Russian revolutions diminished the prestige of religious institutions to such an extent that it was widely believed that religions would soon go out of existence. However, when the Soviet Union disintegrated, the Orthodox Church resurfaced as a powerful social institution, and Muslim peoples reunited with Islam. Although the Vatican represents the Catholic religion from Europe, Christianity sustains its fervor in the United States and particularly in Latin America. On the other hand, Islam has entered into a new stage of revitalization from the 1980s onward.

As the historic Hagia Sophia was reopened as a mosque, historical issues have come to the fore in the public debate. Some in the international arena have raised the question: How did the Ottomans treat non-Muslim peoples? Meanwhile, European countries do not bring their own history under international scrutiny: the deaths of millions of people in Africa, Asia and the Americas due to a process of savage colonization, the deaths of 1.5 million people in the Algerian resistance against the French, the deaths of millions in the occupations of Afghanistan and Iraq, and so forth. These issues have not been questioned in the international debate, as the West represents "progress" while the rest of the world represents "backwardness."

Religions always played a key role in the formation of peoples, countries and states. For instance, Western thought took shape under the influence of Catholicism. As Judaism has been seen in Catholicism as the religion that carried out the crucifixion of Christ, Jewish people long lived in ghettos in Christian cities. The anti-Semitic perspective of Catholicism must have contributed even to the Holocaust. While Islam has also been seen as a heresy in Catholicism, European cities during the Middle Ages were largely less populated and religiously homogenous.

However, from the perspective of Islam, as the last religion, both Judaism and Christianity are divine religions, and Jesus Christ and Moses are prophets. Therefore, the religious laws of Christian and Jewish peoples were respected in Islamic cities which were prosperous, crowded and religiously cosmopolitan during the Middle Ages.

For five centuries, the Ottoman state structure ruled over the European lands. As the Ottoman "millet system" ensured that each religious community could live according to its own religious law, the Ottomans protected and sustained the social and religious lives of Jewish and Christian peoples from any denomination. Thanks to such a system of religious respect and recognition, the Ottomans succeeded in ruling over a vast empire that was composed of numerous peoples from different religious and ethnic origins.

During the infamous Sack of Constantinople, Latin Crusaders occupied and destroyed the Christian city of Constantinople. When the Ottomans conquered the city, however, they respected and protected both the Christian people and Christian churches. The Hagia Sophia was turned into a mosque by Sultan Mehmed II as a "right of the sword," but its Christian past was protected. Today, the Turkish government followed in the footsteps of its ancestors by reopening Hagia Sophia for prayers as a mosque while protecting its Christian past at the same time.