Voting is informed by your faith, and I definitely support everyone to vote in faith because "everything that does not come from faith is sin." This I take from Romans 14, which I think can be applied quite a bit to politics.
This pericope is about those in the Church judging others for the meat their eating which may have been sacrificed to idols. Some in the congregation thought the meat was tainted because it was used for pagan rituals, and others knew it was OK to eat because paganism has no power, only the Lord of Hosts has power. There is no conflict between different gods, there is only one God.
I want to use it with politics because we have pastors misusing the name of God to support candidates. They basically write off Democrats as non-Christian for voting the way they do (and vis-versa). Even though you might have the conviction to vote a certain way, you should not judge a fellow believer who voted differently.
If I might rephrase verses 17 through 20a:
For the kingdom of God is not a matter of voting and party affiliation, but of righteousness, peace and joy in the Holy Spirit, because anyone who serves Christ in this way is pleasing to God and approved by men. Let us therefore make every effort to do what leads to peace and to mutual edification. Do not destroy the work of God for the sake of elections.
This Sunday my pastor taught a politically subversive message without his knowledge. He was teaching about where we put our treasure, on earth or in heaven (Matthew 6:21). He was talking about materialism and money, but it is a deep issue that transcends mammon. The pastor quoted somebody (who's name I forget) who said we should live for "the line" not "the dot." The "dot" is now, and the "line" is eternity. America exists in the dot. Politics exist in the dot. War exists in the dot. Borders exist on the dot.
If we could live on the "line" with an eternal perspective, couldn't we really see some unity in the Church?
He also brought forth the quote from Jim Elliot who said, "He is no fool who gives what he cannot keep to gain that which he cannot lose." What a statement!
We cannot keep America. We cannot keep our political parties. We cannot keep our money. We cannot lose the Kingdom of God. We cannot lose the Bride of Christ.
St. Augustine said, "The Church is a whore, but she’s still my mother." What an appropriate quote to include here. We have disagreements, we have sins and filth, but we are still holy in the sight of God, and we are each others. We should love one another.