History unfortunately leaves some people oppressed and some people oppressors. And there are three ways that individuals who are oppressed can deal with their oppression. One of them is to rise up against their oppressors with physical violence and corroding hatred. But oh this isn’t the way. For the danger and the weakness of this method is its futility. Violence creates many more social problems than it solves. And I’ve said, in so many instances, that as the Negro, in particular, and colored peoples all over the world struggle for freedom, if they succumb to the temptation of using violence in their struggle, unborn generations will be the recipients of a long and desolate night of bitterness, and our chief legacy to the future will be an endless reign of meaningless chaos. Violence isn’t the way. Another way is to acquiesce and to give in, to resign yourself to the oppression. Some people do that. They discover the difficulties of the wilderness moving into the promised land, and they would rather go back to the despots of Egypt because it’s difficult to get in the promised land. And so they resign themselves to the fate of oppression; they somehow acquiesce to this thing. But that too isn’t the way because non-cooperation with evil is as much a moral obligation as is cooperation with good. But there is another way. And that is to organize mass non-violent resistance based on the principle of love. It seems to me that this is the only way as our eyes look to the future. As we look out across the years and across the generations, let us develop and move right here. We must discover the power of love, the power, the redemptive power of love. And when we discover that we will be able to make of this old world a new world. We will be able to make men better. Love is the only way.

There's a good summary of MLK's overarching theme, for his movement.