Matthew 7:6 Do not give the holy thing to the dogs, and do not throw y o ur pearls before swine lest they trample them with their feet, and after turning they tear y o u in pieces.
I've often been very puzzled by this verse and how to apply it. The verse is usually interpreted as meaning something like, "If people continue to reject the true doctrine just stop bothering them with it or they might beat you up." It seems too easy for my sinful nature just to decide that somebody is hopeless and eternally damned so I ought not to try and bring them the Gospel anymore.
Dr. Jeffrey Gibbs provides a better explanation. The verse should be interpreted in context.
Matthew 7:1-6 "Do not be judging, so that y o u may not be judged; for y o u will be judged by the judgment with which y o u judge, and it will be measured to y o u by the measure with which y o u measure. And why are you trying to see the speck in your brother's eye, but you do not consider the beam in your eye? Or how will you say to your brother, 'Please let me take out the speck from your eye'; and look, the beam is in your eye? Hypocrite! First take out the beam from your eye, and then you will see clearly to take out the speck from your brother's eye. Do not give the holy thing to the dogs, and do not throw y o ur pearls before swine lest they trample them with their feet, and after turning they tear y o u in pieces.
If verse 6 is read in context, it becomes clear that the "pearls"/"holy thing" are not true doctrines but brothers in Christ. The "pearls" are the same as the brother with the speck in his eye. The passage is warning against hypocritically judging our Christian brothers. We should not cast them out of the church because they don't measure up to some standard that we have created. When we see the sins of others (if they are really sins and not just things we don't like), this should call us to self-examination and to the realization that it is only by the grace of God that we do not fall into the same sin. We should approach our brother in humility and with a genuine concern and love for our brother--not the hope of making him look bad.
The danger is that a wrong interpretation of this verse could lead a person to go tell his brother in Christ what he is doing wrong and when the person disagrees to conclude that the person is swine. The Lamb did not come to shed His blood for righteous speck removers, but for real sinners. If you cast God's holy treasures to the swine, you will be judged and torn in pieces.