Let me ask you a question: What would happen to our nation if everyone decided not to vote? You know the answer -- before long we'd lose our freedoms and be ruled by a power-hungry dictatorship. No system of government is perfect, including ours -- but all it will take to make it collapse is an indifferent citizenry.
But I also urge you to vote for another reason: I believe it is a God-given responsibility. When Jesus walked this earth, the whole civilized world was under the authority of one individual: the Roman emperor (or Caesar). He wasn't elected by popular vote, nor did ordinary people have an opportunity to express their views through the ballot box. And the Roman government wasn't perfect; in fact, it promoted paganism and could be brutal.
And yet Jesus taught that people still had a responsibility to encourage and support their government in every way they possibly could. He said, "Give to Caesar what is Caesar's, and to God what is God's" (Matthew 22:21). The same principle is true for us today: We should do everything we can to encourage and support good government -- including voting. Understand the issues...know where the candidates stand on them...ask God to guide you -- and then vote.
Beyond that, however, pray for our nation and its leaders -- not just the President, but all who've been entrusted with public office. It's the most important thing you can do. The Bible commands us to pray for "all those in authority, that we may live peaceful and quiet lives in all godliness and holiness" (1 Timothy 2:2).