We don't need to advertise ourselves to let people know our faith and the kind of God we serve. Jesus says in Matthew 5:16 that our light should shine in us to let people see it and glorify our father in heaven. When Moses was from the presence of God the second time, his face shone that he had to put a veil on himself. God searches our hearts more than what ordinary men consider to be godliness. 2 Corinthians 3:2 says we are written epistles read and known by all men. The only way we let people know God is through our character.