Here is the thing with theists in America at least. The only interaction with those who claim they are atheists (as opposed to those who frankly don't give a shit about their own beliefs) ends up solidifying the negative stereotypes they already have....it would be like an atheist going outside and the only Christians they meet are from the WBC.
But if we walk in the light, as He is in the light, we have fellowship with one another, and the blood of Jesus, His Son, purifies us from all sin.