The Qur’an (109: 1-6) addresses those who do not believe in Islam:
"(O Muhammad tell the unbelievers;) O unbelievers, I worship not what you worship nor do you worship what I worship. And I shall never worship what you worship, nor will you worship what I worship. You have your religion (din) and I have my religion (din)." Al-Kafirun, 109:1-6.
No other religion makes it as clear as Islam does that its adherents must respect all other religions. Religion here is any and every set of beliefs or values practiced by a group of people; it does not matter how different from Islam it is.
For example, in narrating the story of Joseph in Egypt the Qur’an refers in (12:76) to "the din of the (Egyptian) King."
But Islam appeals to the intellect and the soul of every person to seek the Truth and it offers the Qur’an as the Way to the Truth.
"(O Muhammad) Verily, We (God) have sent down to thee the Book (the Qur’an) with the Truth. So worship / serve God, making the din sincere for Him." Al-Zumar, 39:2
Here God in the Qur’an addresses Prophet Muhammad directly and asks him to serve God. The Arabic word "din" has different meanings and here it is usually translated as "devotion."
According to Dr. Wilfred Cantwell Smith, the word "religion" in general may be taken in two different, although closely related, senses; one is "religion" as a deep personal matter; the existential act of each individual person of believing in something, that is, in short, "faith"; and the other is "religion" in a "reified" sense, i.e. as something common to a community, an objective communal matter, comprising all the creeds and ritual practices shared by all members of that community. Both of these meanings are found in the Qur’an.
In 16:52, after stating that because "Whatever exists in the heavens and on earth belongs to God," the Qur’an concludes that the only True faith (din) is faith in the True God, the One, the Absolute, the Infinite and Perfect. In the Universe you cannot logically have more than one Absolute, Infinite and Perfect Being.
"I (Muhammad) have been commanded to worship / serve God making my religion (din) pure and sincere." Al Zumar, 39:14
The Qur’an seeks and promotes every commonality between Muslims and non- Muslims. The most common one is simply being human, tracing our origins back to one man and one woman. Another is all our shared values for kindness and honesty. And most important, is the value of seeking justice for all.
The Qur’an calls all true followers of the Prophets Muslims, including the true followers of Abraham, Moses, Jesus and Muhammad.
"As for me (Muhammad) my Lord has guided me to a straight path, a right religion (din) the religion (millah) of Abraham who was a man of pure monotheism." Al-An’am, 6:162
Islam advocates humble submissions to the Almighty with the understanding that it is God’s will that humans should believe in different religions, or even in no religion. The respect of that Divine will is a must and the respect of each other religions is necessary.