I became a Christian in 1981 and started attending an assembly of God church. I was shocked to discover that one of the young married couples there were big carter supporters and bugged by Reagan’s election. I thought, how can you be a conservative and be in favor of a democrat.
And then I remembered something that was not big on my radar before that: Carter was the “Christian” candidate.
Interestingly, I learned in that same church that one of the meanings of using the Lord’s name in vain is using your Christianity for personal gain, e.g. putting the Christian fish on your business card.
Many a sinner does exactly that for his own self-serving purposes.
One result is that when people recognize the true nature of these manipulators, it makes God look bad in the world's eyes, this behavior being a false representation of God's nature. After all, these are his dedicated "believers". IOW, in their day-to-day actions, certain religous folk perpetually bear false witness.
Compare:
Chillul haShem (Hebrew: חילול השם desecration of the Name), meaning desecration of the name of God, is a term used in Judaism for any act or behavior that casts shame or brings disrepute to belief in God, any aspect of the Torah's teachings, Jewish law, or the Jewish community.http://en.wikipedia.org/wiki/Chillul_Hashem
The name of God is thereby blasphemed among the nations by these false witnesses.
God is not mocked.