Today is the King holiday, the celebration of a religious man who spoke out for civil rights in a non-violent way using scripture to make his point. As seen in his "Letter from the Birmingham Jail" (My Dear Fellow Clergyman), Reverend King believed that equality was very much a biblical tenet. Indeed, Black Liberation Theology takes some of its roots from King's ideology.
Yet for some reason today he's more often referred to as "Doctor" King rather than a reverend. Maybe that's an attempt to respect his educational achievements but it's almost as if the modern narrative seeks to reduce the faith-based aspect of his message and instead concentrate on its largely political by-product: "social justice" (not all reverends or Christians believe as King did on the definition of social justice within our system). However, the popular definition lines up much better with mainstream liberal orthodoxy, even to include projecting King's blessing of Occupy Wall St. and the like.
It's true King's use of Christianity wasn't just fodder for a sermon, it was in part an appeal to the white (predominately Christian) majority to see the plight of the Negro from a biblical perspective. Ironically, secular humanists today see no problem celebrating King's legacy while taking no issue with his worship of an invisible sky man. For instance, we're told that one cannot cherry-pick the Bible, ie, if referencing Matthew one must also defend the anti-homosexual passages of Leviticus, so perhaps the Reverend King would find it harder to promulgate his message in today's world. Theoretically, at least.