If people wish to influence society then standing for election is a good way.

Yes, but so is, say, becoming a senior executive of an NGO and I'm not sure that my elected representative understands all issues well enough without hearing them discussed by knowledgeable people in a formal environment.

That's mainly to Steve's topic drift House of Lords discussion, but the argument applies to faith leaders who have specialist knowledge of their communities.

Politicians, by the nature of the game, make 'unholy' (in the metaphorical sense) alliances. People representing special interest groups can't do that so easily. I think government needs both those who have to compromise to get things done and those who don't need to.