The church is married to the Messiah of the Kingdom of God.  For the church to climb into bed with the governments of earth and allow itself to be used is to commit harlotry.  Further, it keeps the church from speaking truth to immoral behavior and unjust decisions.  When we put the the things of the eternal Kingdom of God on the back burner so that we can gain temporal power, the prophetic voice is sold for a mess of pottage.  Yes, we must be salt and light, but we must never put ourselves in a position to be neither.  The prophetic voice makes no peace with oppression, nor sin in high places.  John the Baptist spoke truth to power and it cost him his life.

But as he (Paul) was discussing righteousness, self-control and the judgment to come, Felix became frightened and said, “Go away for the present, and when I find time I will summon you.”  Acts 24:25 (NASB)