Sunday Readings Commentary

We need to start thinking again about genuine conversion, turning back to the Lord. This passage comes far on in the Book of Isaiah, written when the Jews had returned from exile in Babylon, but still things were not going right for them, still the favour of the Lord did not seem to be upon them. It makes a good examination of conscience: do I invite the homeless poor, share my advantages with others? Am I at peace with my family? Do I seek to dominate by the ‘clenched fist’, the wounding word, the put-down which can shrivel someone up?    Isaiah is contrasting genuine service of the Lord with the merely exterior practices of religion, the conventional ways in which we may seem to be ‘holy’ people. In fact, however, holiness is all a matter of the heart, and – at any rate in this text – mostly a matter of seeing and serving God in other people. That is the only way our light can really shine in the darkness, and our own wounds be healed over. As in the Beatitudes, God’s demands always have a promise attached.

What was the secret of Paul’s success? At times he seems to us boastful, ‘Take me as your pattern’ (4.17) or ‘Be united in imitating me’ (Phil 3.17). He boasts of his faultless Jewish ancestry: ‘Are they Hebrews? So am I’ (2 Cor 11.22), etc. He claims to have undergone for Christ more sufferings and persecutions than others (2 Cor 12), to have been perfect in the Law (Phil 3.6), to have outstripped his contemporaries in his zeal for the Law (Ga 1.14). He claims that he speaks in tongues more than any of them, and yet he does not make much of it (1 Cor 14.18). Yet here he insists that he came among the Corinthians in weakness, in fear and great trembling in order to make known the power of the Spirit. In the same way he will later admit that he holds the treasure of the light of Christ in fragile pots made of earthenware (2 Cor 4.7). There are some wonderful rhetorical passages in Paul, where he exploits to the full the literary and oratorical training he had received, but in the last analysis one must admit that his power consists simply in the power of his message and the promises of Christ.

These sayings about salt and about the light of a lamp come in various places in the Gospels, to challenge or encourage the disciples of Jesus. In Mark the saying about salt is joined to other sayings about salt, not by logic but simply by the catch-word ‘salt’. Here in Matthew, right after the opening promises of the Sermon on the Mount, they are surely a challenge to the disciples – not the Twelve, but all the disciples of Jesus, both those who kept company with Jesus and those who have followed after.

The image of salt is obvious enough: food cooked without salt can be bland and tasteless, utterly unexciting. So a half-hearted or shallow proclamation of the gospel wins no converts. The message of the gospel must be piquant, sharp and challenging. If it does not change the life and temper of the hearer it has lost its piquancy and may as well be thrown out. The proclamation of Jesus aroused annoyance and opposition; the same will no doubt be the case in the world of today.

The image of a lamp is gentler and wholly positive. Think of the flame of a small oil-lamp in the darkness of a large one-roomed house! Under a tub or a bowl or even a bed it will have no effect at all on the darkness, but on a lamp-stand it can bring light into the farthest corners, make social life and activity possible and bring joy to a whole family and its friends.
At the beginning of the Sermon these two images challenge disciples to share the salt and the light of the message they will receive with all who have ears to hear.