This is a 2-part John MacArthur sermon series from Titus about a Christian's role in a pagan society:
It's a very eye-opening look at what our role in modern America should be, because the United States could not be classified as anything but a pagan society at this point. But that's okay, because there is absolutely nothing in the Bible that requires us to "impact the culture". Our job is to spread the Gospel of Christ, not to attempt to legislate morality upon our nation.
MacArthur gives an excellent quote from John Seale in the second part of this sermon (emphasis added):
Our primary citizenship is not on earth but in heaven. Though few evangelicals would deny this truth in theory, the language of our spiritual citizenship frequently gets wrapped in the red, white and blue. Rather than acting as resident aliens of a heavenly kingdom, too often we sound like and act like resident apologists for a Christian America. Unless we reject the false reliance on the illusion of Christian America, evangelicalism will continue to distort the gospel and thwart a genuine biblical identity.
I think this is really important to keep in mind as we are heading into the upcoming election.