I think it's comforting to go back to the famous formula "God became man so that man might become God." If all the Orthodox Christians were putting this through practice, there would be no atheism. It gives a whole new meaning to "lights of the world and salts of the earth." We don't prove God's existence by arguments, even though they're entertaining and somewhat helpful, but most importantly we live God and we have God in us. No greater proof for the atheist and agnostic than to see the God in you.
God bless you.