Even if there is no God, I value my own life and would prefer to keep living out my natural lifespan. A society that does not have rules against murder would very quickly spiral out of control.
Rules protecting life are a neccesity for any functional society.
Even Dawkins doesn't believe in pure randomness. If everything were purely random then there would be no basic laws of physics. As soon as you have basic laws of physics, then you have boundary conditions, allowed and disallowed states, etc. So although popularized texts about evolution might use terms like "purely random" this is a misnomer.
In any case, my main point is not to prove or disprove God's existence, but to make the reasonable claim that Christians can engage in useful philosophical dialog with non-Christians. God made the world, and God made us in His image. Because of this, non-believers of goodwill will come to similar conclusions as Christians. Because of this we as Christians can join with non-Christians and create workable societies that are better than what the Commies, or Fascists, or Socialists came up with.
We can theoretically convince Dawkins that private gun owernship is a good thing without having to first prove to him the existence of God. We can convince some people through purely scientific reasoning that abortion is the killing of an innocent human life.
Why not take advantage of this fact? If we can't engage in useful dialog with non-believers then the only rational options are to either stop everything we are doing and spend all of our time evangelizing, or move to the middle of the forest.
If the Republican Party and/or "conservatives" are ever going to be important components of the political process then we need to be able to work with non-believers or believers who believe differently than we do.
Reagan got union members to vote for him, for gosh sakes! How the heck did a rightwing Republican accomplish that?
We should be able to work with libertarians, independents, anti-statist liberals, etc. to implement good legislation and remove bad legislation.
And we don't need to first get everyone to become born again and baptized in the nearest river.