Some imperatives call for negative action: "Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you." (Matthew 7:6)
With the Spirit inside us we are admonished in Matthew 7:6 to be careful of offering holy and pure Gospel truths to those who are only snarling dogs, waiting to tear them apart for their own vicious pleasure. In this day and age of instant social contact through blogs, Twitter, Facebook and other media, Gospel outreach is all the more prevalent. But so is the ease with which the dogs and swine mock and scoff.
"Knowing this first, that there shall come in the last days scoffers, walking after their own lusts, And saying, Where is the promise of His coming?" II Peter 3:3-4
So how do we react to those who reject the Gospel in such a ferocious fashion?
"Jesus’ point is that certain truths and blessings of our faith are not to be shared with people who are totally antagonistic to the things of God. Such people are spiritual dogs and swine, who have no appreciation for that which is holy and righteous. They will take that which is holy, the pearls (the rarest and most valuable of jewels; see Matt. 13:45–46) of God’s Word, as foolishness and as an insult. A wild animal whose main concern is scavenging for food will not appreciate being thrown a pearl. He will resent its not being something to eat and possibly attack the one who throws it. Dogs and swine represent those who, because of their great perversity and ungodliness, refuse to have anything to do with the holy and precious things of God except to trample them under their feet, and turn and tear God’s people to pieces. In Revelation 22:15, they are classified with sorcerers, whoremongers, murderers, idolaters, and whosoever loveth and maketh a lie." As John MacArthur admonished in his sermon "Casting pearls before swine".
"The admonition of the Lord in our text then clearly means that his disciples shall not give, nor minister the gospel, or its provisions, its promises, its comforts, its ordinances, or any of its commands, to any who are thus designated dogs, or who are in nature, disposition, practice or appetite as unlike the regenerated and spiritual people of God as dogs are unlike and inimical to the sheep and lambs." Gilbert Beebe (1800-1881)
"When people not only reject the gospel, but insist on mocking and reviling it, we are not to waste God’s holy Word and the precious pearls of His truth in a futile and frustrating attempt to win them. We are to leave them to the Lord, trusting that somehow His Spirit can penetrate their hearts-as He apparently did with some of those who at first rejected the preaching of Paul and the other apostles-or leaving them to the just judgment of God." [MacArthur]
It's clear that the imperative to go and make disciples of all nations does not include those who are reviling of the Gospel. You have already offered them the highest, and they have countered with the lowest, content to remain in the muck as swine do. They refuse to lift up, and in choosing to continue a conversation, there is no place for you to go but down. Rather than arguing with them over the most beautiful of truths, it is OK, even preferred, to leave them alone. In those cases, the faithful Holy Spirit will enact His will on those lost and brutal souls. The Holy Spirit shall "guide you into all truth... he shall take of mine, and shall shew it unto you." (John 16:13-15).
The age of Twitter and its 140 characters means easy outreach to all, but it is superficial to the sinner. See LR Shelton's presentation of the process through scripture:
"The sinner must first be awakened by the Holy Spirit before he can be enlightened, according to Eph. 5:14, "Awake thou that sleepest, and arise from the dead, and Christ shall give thee light."
"Second, he must be enlightened before he can he convinced or convicted: "And when he is come, he will reprove (convince) the world of sin, and of righteousness, and of judgment."
"Third, the sinner must be convinced before he can be wounded to death by the "sword of the Spirit" (Rom. 6:3-4) "So many of us as were baptized into Jesus Christ were baptized into his death."
"Fourth, the heart of the sinner must be wounded and broken before it will turn from sin to the Lord Jesus Christ for salvation (Psa. 38:8-9), "I am feeble and sore broken: I have roared by reason of the disquietness of my heart. Lord, all my desire is before thee; and my groaning is not hid from thee."
"Fifth, the heart of the sinner must turn to Christ (Joel 2:13), which is repentance, and run after Him (Song of Solomon 1:4), seeking Him with all the heart (Psa. 69:32), "Your heart shall live that seek God," and (Jer. 29:13), "Ye shall seek me, and find me, when ye shall search for me with all your heart." That is faith."
By all means, use social media and personal witness to encourage the brethren, and employ all possible means to introduce the lost to Jesus. But leave the mockers and scoffers alone, and do not persist in casting pearls to swine and dogs.