The separation of church and state should be important to you regardless of what your religious views are. It is truly the basis of our American liberties. Without separation of church and state, we could easily have some form of theocracy. The problem is: Would the government reflect your views or those of some other denomination? Would you be a member of a minority religion that keeps losing power or a majority religion that keeps gaining power? Would you end up always wearing a head scarf in public or saying your favorite prayer over the loudspeaker at school every day? Would you be able to wear makeup and jewelry or use birth control? Would you be required to have your foreskin ceremoniously removed on your 14th birthday or a religious tattoo placed on your left bicep?
While we don't have to worry about that yet, we do need to vigilantly guard the church/state division. One way this is done is through the tax code. A church is exempt from income tax if it is a 501c3, but if it starts becoming political, it may lose that status. Churches are also exempt from property taxes. But, if a church allows a candidate to use the church as a campaign headquarters or use it to hand out literature or campaign signs, that's a problem.
The next time you observe a too cozy relationship between a political candidate and a church, yell, write a Letter to the Editor, tell the attorney general or the IRS, or check out a site such as www.au.org (Americans United for Separation of Church and State).