Great quote on the what it meas to be a Christian – at least one aspect of it – from The Doctor:
“The true Christian cannot be hid, he cannot escape notice. A man truly living and functioning as a Christian will stand out. He will be like salt; he will be like a city set on a hill, a candle set upon a candlestick. But we can also add this further word. The true Christian does not even desire to hide his light. He sees how ridiculous it is to claim to be a Christian and yet deliberately to try to hide the fact. A man who truly realizes what it means to be a Christian, who realizes all that the grace of God has meant to him and done for him, and understands that, ultimately, God has done this in order that he may influence others, is a man who cannot conceal it. Not only that; he does not desire to conceal it, because he argues thus, ‘Ultimately the object and purpose of it all is that I might be functioning in this way’.”
– Martin Lloyd-Jones, Studies in the Sermon on the Mount.