This is one of my favorite essays on MLK-related themes. The author is Phillip Yancey:
Occasionally, grace and power descend on great and flawed leaders to convict and lead us on. In the end, it was not King's humanitarianism that got through to me, nor his Gandhian example of nonviolent resistance, nor his personal sacrifices, inspiring as those may be. It was his grounding in the Christian gospel that finally made me conscious of the beam in my eye and forced me to attend to the message he was proclaiming. Because he kept quoting Jesus, eventually I had to listen. The church may not always get it right-and it may take centuries or even millennia for its eyes to open-but when it does, God's own love and forgiveness flow down like a stream of living water. Alas, by the time I tasted of that stream, King was already dead.
Read the rest here.