Salaams to all.
Sorry I disagree.
To believe in God, His Books and Prophets is religion.
Hence, Islam is not entirely secular and entirely religious. It is an intersection of both, the secular and religious.
Thus, one of its main functions is to eliminate the dichotomy of the secular and religious and all extremists and fundamentalists teachings and practices within and between them that makes them separate and exclusive.
At a more sophisticated level of life, it superimposes the knowledge of science, religion, culture, politics, etc, one on top of the other without creating any boundaries within and between them that make them separate and exclusive.
The Prophet (s) is a very prominent example of this knowledge of Islam in world history. He was only one who was “most extremely successful in both the secular and religious levels”. Reverend Bosworth Smith said “he was Pope and Caesar in one”.
Hence, Islam is almost 100% compatible with secular democracy. The only difference is the Islam distinguishes the God-given Diversities from those that are made by man, which the secular constitution fails to do.
I discuss this aspect of Islam in my new E-book titled “ABRAHAM’S FAITH: Post-Modern Way of Life, not Religion” in great detail. For more information on the E-book visit my Website at http://www.thepostmodernway.wixsite.com/info