Source / Courtesy: Alislam-eGazette
By Abdul Haq Compier
Islam presents a policy of religious tolerance, rooted in teachings on the universal nature of man, his free relationship to God, and the divine origins of other religions. The prophet Muhammad separated his authority as a religious leader from his position as a governor, creating a religiously diverse society from the very start. This contrasted to the Christian world, where men were regarded to be born in original sin, only to be redeemed by Christ through the one true Church. Ever since the Byzantine Empire, Christian rulers had governed by the motto ‘One State, One Law, One Faith’, leading to horrendous persecutions of heretics. Throughout history, persecuted Christians have noticed the contrast to the tolerance within Islam. When, in the 16th century, persecutions in Europe became unbearable, Christian advocates of tolerance referred to the Ottoman Empire as the model to adopt. The example of the empire was offered in debates on tolerance from Hungary to Germany, France, the Netherlands and Great Britain, up until the 18th century, by tolerance advocates such as Sebastian Castellio, Francis Junius, John Locke and Voltaire. The Netherlands became a junction, adopting not only the Ottoman model of religious diversity, but also receiving political and
military support from Ottoman sultans.
Is the West ready for Islam? 
Zia H. Shah
If it’s his region, it’s his religion!
Eventually, after some back and forth and some fighting, in 1555, we get the Peace of Augsburg, a permanent settlement between the emperor and the German princes, which settles everything under the principle that I mentioned earlier, cujus regia, ejus religio, which means “if it’s his region, it’s his religion.” If you’ve got a territorial prince who’s a Lutheran, then his territory is Lutheran. He gets to foster the Lutheran Church. If you get a territorial prince who’s Catholic, he gets to foster the Catholic religion. And they’re supposed to live in peace with each other, tolerate each other; let Lutherans leave Catholic territories in peace and move to Lutheran territories. There’s a kind of uneasy but genuine commitment to not killing each other over their religion in the future.
Religious warfare broke out later. They did kill each other over religion in the 30 Years’ War in the 17th century, which ended in 1648 with the Peace of Westphalia, which again reinforced that cujus regia, ejus religio principle. Once again, you have the Lutheran princes and the Catholic princes. You also ended up having tolerance extended to the Reformed people, not the Lutherans; they also then get equal rights-so, you have a rationale of religious toleration developing, and that becomes one of the crucial aspects of modernity .
In the Middle Ages, you’d have religious warfare, where the church might suppress heresy, the Albigensian Crusades, where the knights went in and attacked heretics in southern France. In the modem period, what you have are state churches, princes who are Lutherans attacking princes who are Catholic. You’ve had Christendom divided, Christendom at war with each other for Christian reasons.
(Prof. Phillip Cary. Luther: Gospel, Law, and Reformation. Teaching Company Course Transcript, 2004. Pages 160.)