Martyn Lloyd-Jones on Matthew 5:13-16
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’.
If we find in ourselves a tendency to put the light under a bushel, we must begin to examine ourselves and make sure that it really is ‘light’. It seems to be a fact about salt and light that they want to manifest their essential quality, so if there is any uncertainty about this, we should examine ourselves and discover again the cause of this illogical and contradictory position. Let us put it, therefore, in this simple form. The next time I find myself with any sort of tendency to cover over the fact that I am a Christian, in order, maybe, to ingratiate myself with somebody else or to avoid persecution, I am just to think of the man lighting his candle and then covering it with a bushel. The moment I think of it like that and see how ridiculous it is, I shall recognize that the subtle thing which offered me that bushel is the hand of the devil. I shall therefore reject it, and shine still more brightly.
Jones, David Martyn. Studies in the Sermon on the Mount. Grand Rapids: Eerdmans. 1959.