The difference is this: evangelism is about speaking truth to power. Politics is about seizing power to defend the truth.
They also wanted there to be no space between what they felt inside and what they did out in the world. They wanted to feel at one with political movements that mirrored how they understood and defined themselves as individuals.
The lesson of these two lessons, so to speak, was that if you want to be a political person you should begin, not by joining a party, but by searching for a movement that has some deep personal meaning for you.
When speaking about themselves, they want to assert their difference and react testily to any hint that their particular experience or needs are being erased. But when they call for political action to assist their group X, they demand it from people they have defined as not-X and whose experiences cannot, they say, be compared with their own.

—
The Once and Future Liberal