"Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven." (Matthew 5:16)
That's a familiar verse that practically interprets itself, with a command ("Let your light so shine before men"); an explanation of what the command entails ("[Let your light shine so] that [people can] see your good works"); and a reason for the command ("[So that people will] glorify your Father . . . in heaven.")
Despite the simplicity of that verse, there's a lot of misunderstanding nowadays about what it means and what it demands of us. The passage and its context are often cited by those who seem to think it's a call for Christians to harness the political process. It seems like every time I hear anyone talk about "salt and light" nowadays, it's someone trying to rally Christians for political activism or persuade evangelical church members to sign onto some boycott, petition, or letter-writing campaign—as if lighting and salting the culture were nothing other than consolidating the evangelical movement behind a political agenda and then making our voices heard in the political process.
But if you look at this passage carefully in its context, it is not talking about political activism at all. It's not talking about using our clout as a voting bloc, or organizing mass boycotts and protests, or electing Christians to public office. It's talking about holy living at the individual level.
Please understand: I have no objection to Christians who run for political office. I have no doubt that God calls some of His people to serve in government, just as He calls some to serve in business, some to teach in universities, and others to work in every segment of society. All society is salted with Christians, and each one ought to have a beneficial effect in his circle of influence, no matter how big or how small that circle of influence may be. Collectively, we all benefit and preserve and season society as a whole. That truth is certainly what this text is about.
But our influence as Christians is most effective at the personal, grassroots level. There's no suggestion in our text that the church's mission is to commandeer the machinery of secular politics in order to wield our influence through political force or clout. If you have the idea that's the best way (or the main way) the church is supposed to influence society, I think you're missing the point of the text.
I hope you vote. I hope you're a good citizen in every way. And I hope you use your vote conscientiously and with discernment. But if your hope for the future of our society rests in the democratic process, or if you think the fortunes of the church rise or fall according to which party is in power, you need to look again at how the people of God have historically made their influence felt in society. You'll discover that those times when the church has grown the most and when revival has spread furthest are times when believers have been most concerned about personal holiness and evangelism.
Political clout is not what we need to influence a hostile secular society like the one in which we live today. All the power and all the politics and all the public policies in the world will never force unbelievers to yield their hearts to Christ as Lord.