(Synoptics: Matthew 7:6) This is about what we say to people who are outside God’s kingdom. Although the subject changes here, this verse corrects any false interpretation of the previous five verses: they do not teach that we must never pass judgement on another; we cannot avoid giving what is holy to dogs or casting pearls before swine without making a judgment about those we speak to.
How do we obey this in context of evangelism? Often we find ourselves speaking to strangers. We do not know in advance what their response will be. Yes, we will not speak to drunks or to the disorderly, but the rest we will have to try to discern as we speak. If they mock, we do not respond by bringing out more and more wonderful truths as if we could overwhelm them with grace.
What do pearls refer to? To times of special closeness to Lord which we would not want to talk to cynics about. We must face the fact that there are some who set no value on the gospel, and would gladly destroy it without any sense of loss. Witness is not such an imperative that we speak even to those who ridicule the message. By their response they may forfeit the right to hear such precious truths.
There is another application of these words. Christ speaks to his disciples among the Jews. See that you do not perpetuate the old order. You are called to belong to the church of Jesus Christ: do not let the unconverted into the Lord’s Supper. The Episcopal church wants a mixed multitude; it wants whole parish to come in regardless of whether they are born again or not; even the Presbyterians do this in a measure. The result is that the world rapidly takes over the church and all is lost. This is also to do with relationships. Do not share the most precious things with outsiders. Your love and tenderness you are to chiefly to be shared with believers. If you make worldlings your best friends and not God’s people, you will fall foul of this. This also applies to churches. We cannot join in with Christian Unity prayer breakfasts with those who preach another gospel and are enemies of the Bible. That is why we cannot be part of the ecumenical movement, for we believe churches are distinctive community of God’s people.
Can mockers do the gospel any harm? No, the truth will stand in spite of all lies of men. The inscription attached to the cross in derision was actually a testimony to the truth.