A secret religion is not Christianity
So impossible it is to keep our religion from being seen, unless we cast it away. So vain is the thought of hiding the light, unless by putting it out. It is sure that a secret, unobserved religion cannot be the religion of Jesus Christ. Whatever religion can be concealed is not Christianity. If a Christian could be hidden, he could not be compared to a city set upon a hill (Matthew 5:14), to the light of the world, the sun shining from heaven and seen by all the world below. Never, therefore, let it enter into the heart of him whom God has renewed in the spirit of his mind (Ephesians 4:23) to hide that light, to keep his religion to himself, especially considering it is not only impossible to conceal true Christianity, but likewise absolutely contrary to the design of the great Author of it.
1771 text
4. So impossible it is, to keep our religion from being seen, unless we cast it away: so vain is the thought, of hiding the light, unless by putting it out. Sure it is, that a secret, unobserved religion cannot be the religion of Jesus Christ. Whatever religion can be concealed, is not Christianity. If a Christian could be hid, he could not be compared to a city set upon an hill; to the light of the world, the sun shining from heaven, and seen by all the world below. Never therefore let it enter into the heart of him whom God hath renewed in the spirit of his mind, to hide that light, to keep his religion to himself; especially considering it is not only impossible, to conceal true Christianity, but likewise absolutely contrary to the design of the great Author of it.