Lol wut? He's saying that power comes from solidarity, and with solidarity you make demands, and when you have power you do not relent until those demands are met. He's also saying that the harm caused by direct action in pursuit of liberty is justified, even when that harm is to everyone (as in the case of a general work stoppage in an entire city). That you don't want to see the relevance isn't something I can help.
The point isn't to cause the harm, it's to use the threat to gain concessions.
Say to everybody in this community that you’re going to stick it out to the end until every demand is met. And that you’re going to say, “We ain’t going to let nobody turn us around.
We can all get more together than we can apart. This is the way to gain power. Power is the ability to achieve purpose. Power is the ability to effect change. We need power…
If we are going to get equality, if we are going to get adequate wages, we are going to have to struggle for it. Now, you know what, you may have to escalate the struggle a bit. If they keep refusing, and they will not recognize the union, and will not decree further check-off for the collection of dues, I’m telling you what you ought to do, and you’re together here enough to do it. In a few days you ought to get together and just have a general work stoppage in the city of Memphis.