John Piper uses 1 Corinthians 7:29-31 to help us think through the paradoxical mindset of Christians when it comes to voting.

Paul says that we are

• to mourn as if we are not mourning,
• to rejoice as though we are not rejoicing,
• to buy as those who have no goods, and
• to deal with the world as those who have no dealings with the world.

If this is so, then we can have a paradigm of of voting as those who do not vote.

1. We should do it. But only as if we were not doing it. Its outcomes do not give us the greatest joy when they go our way, and they do not demoralize us when they don’t. Political life is for making much of Christ whether the world falls apart or holds together.
2. There are losses. We mourn. But not as those who have no hope. We vote and we lose, or we vote and we win. In either case, we win or lose as if we were not winning or losing. Our expectations and frustrations are modest. The best this world can offer is short and small. The worst it can offer has been predicted in the book of Revelation. And no vote will hold it back. In the short run, Christians lose (Revelation 13:7). In the long run, we win (Revelation 21:4).
3. There are joys. The very act of voting is a joyful statement that we are not under a tyrant. And there may be happy victories. But the best government we get is a foreshadowing. Peace and justice are approximated now. They will be perfect when Christ comes. So our joy is modest. Our triumphs are short-lived—and shot through with imperfection. So we vote as though not voting.
4. We do not withdraw. We are involved—but as if not involved. Politics does not have ultimate weight for us. It is one more stage for acting out the truth that Christ, and not politics, is supreme.
5. We deal with the system. We deal with the news. We deal with the candidates. We deal with the issues. But we deal with it all as if not dealing with it. It does not have our fullest attention. It is not the great thing in our lives. Christ is. And Christ will be ruling over his people with perfect supremacy no matter who is elected and no matter what government stands or falls. So we vote as though not voting.

You can read the whole thing, with further explanation of Paul’s paradigm, here.