One of my favorite bumper stickers of all time said, "Do not meddle in the affairs of dragons, for you are crunchy and good with ketchup." Point taken, bumper sticker, point taken. There are just some things best left alone, things it behooves us not to stick our noses into, if you will. When it's really none of our business, it's time to step back.
Of course, many things are our business, and there are definite times for meddling (just not like Scooby-Doo). Ours is not a private faith, after all, not something meant to exist only in the shadowy corners of our own homes. We are called to publicly live out our faith, to let our Christianity explicitly guide how we act and how we interact in the public realm. This means our shopping habits, the restaurants we visit, how we vote, our movie choices, you name it. And when something clearly stands against the word and will of God, we meddle, speaking truth and words of holiness into that situation.
We do that on a national scale by adopting the word of God to the Jewish exiles in Jeremiah 29:7: "Also, seek the peace and prosperity of the city to which I have carried you into exile. Pray to the LORD for it, because if it prospers, you, too, will prosper." We should therefore do everything we can to promote the peace and prosperity of our country while speaking against the things which will harm it. That could take the form of volunteering, lobbying, voting, or something else. That's our "meddler's mandate."
But we do all this in love. We remember the God who meddles in history, who became a man and stepped into a specific place at a specific time. We remember His love for us all.