Matthew 7:6 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.
Pearls refer to the gospel which is composed of ‘the things concerning the kingdom of God, and the name of Jesus Christ’. This we see in Acts 8:12.
Acts 8:12 But when they believed Philip preaching the things concerning the kingdom of God, and the name of Jesus Christ, they were baptized, both men and women.
Not casting pearls before swine is a principle that we find in Proverbs.
Proverbs 23:9 Speak not in the ears of a fool: for he will despise the wisdom of thy words.
A fool in context is one that does not believe God. There is no point in continuing to preach the gospel to people who refuse to listen.
Matthew 10:14 And whosoever shall not receive you, nor hear your words, when ye depart out of that house or city, shake off the dust of your feet.
Luke 10:10 But into whatsoever city ye enter, and they receive you not, go your ways out into the streets of the same, and say, 11 Even the very dust of your city, which cleaveth on us, we do wipe off against you: notwithstanding be ye sure of this, that the kingdom of God is come nigh unto you.
The problem is highlighted in the parable of the marriage of the king’s son. Some made light of the invitation, others maltreated and killed the messengers.
Matthew 22:2 The kingdom of heaven is like unto a certain king, which made a marriage for his son, 3 And sent forth his servants to call them that were bidden to the wedding: and they would not come. 4 Again, he sent forth other servants, saying, Tell them which are bidden, Behold, I have prepared my dinner: my oxen and my fatlings are killed, and all things are ready: come unto the marriage. 5 But they made light of it, and went their ways, one to his farm, another to his merchandise: 6 And the remnant took his servants, and entreated them spitefully, and slew them.
In Paul’s day the Jews were the main problem; because they refused the gospel, Paul and Barnabas turned from them to preach to the gentiles.
Acts 13:45 But when the Jews saw the multitudes, they were filled with envy, and spake against those things which were spoken by Paul, contradicting and blaspheming. 46 Then Paul and Barnabas waxed bold, and said, It was necessary that the word of God should first have been spoken to you: but seeing ye put it from you, and judge yourselves unworthy of everlasting life, lo, we turn to the Gentiles.
The opposition of the Jews often turned into violence.
Acts 14:19 And there came thither certain Jews from Antioch and Iconium, who persuaded the people, and, having stoned Paul, drew him out of the city, supposing he had been dead.
The Jews stopped their ears because they could not endure to hear the truth from Stephen.
Acts 7:57 Then they cried out with a loud voice, and stopped their ears, and ran upon him with one accord, 58 And cast him out of the city, and stoned him:
It is a failing in men, exhibited in many ‘religions’, that they easily justify the killing of others whose reasoning is contrary to their ‘traditional beliefs’. We should learn from the failure of the Jews and make sure that our reasoning is firmly rooted in the scriptures and not adulterated by the traditions of men.
Mark 7:7 Howbeit in vain do they worship me, teaching for doctrines the commandments of men.
In conclusion: There is nothing to be gained by preaching to people who cannot be persuaded by reasoned argument from the scriptures.
Titus 3:10 A man that is an heretick after the first and second admonition reject; 11 Knowing that he that is such is subverted, and sinneth, being condemned of himself.
Faith or belief has to be in accordance with, not in spite of, scripture.
Romans 10:17 So then faith cometh by hearing, and hearing by the word of God.
Those who will not hear will not believe.
I hope you have found this helpful.
May God bless you,