We can be sure this method of controlling speech will work for most people, even believers. In the past believers were choosing to withhold judgment and speech in favor of fitting in to be accepted by the world, why would we think they would display greater strength in the face of stricter more devastating rejection?
For years I have spoken boldly on matters of morals and God's principles. In most cases the declaration of God's view of the matters of life, have been met with hostility and judgments against my character, such as "mean spirited", "hateful", and other superlatives to describe a character that would seek to harm instead of to help, mostly by those who claim to be believers. Not only was my speech openly opposed, I was isolated and set apart for dismissiveness to minimize my views in the presence of others.
When I spoke against the sin of "self esteem" some 30 years ago, even as a fairly new believer, I was chastised and shouted down by those who were suppose to know the Word better than I did. They had been indoctrinated into believing that loving one's self was very important to our existence, when in fact, God told us that we are born loving ourselves too much, to the level of godlike status, the goal was to love our neighbor as much as we already love ourselves. God told us to deny self, serve others and worship God above any and all other things and people. When I would attempt to bring the Word of God into the discussion I was quickly shouted down and mocked.
Self esteem teaching is one of the modern sacred cows one is never suppose to touch. Messing with someone's personal choices through preaching or teaching has become a hanging offense, at least among pretenders and the world.
Let me add to all this, if we walk in fear that we may possibly chase someone off because we have addressed sin in the heart of the rebellious, then those same rebellious hearts are not ready to be taught by Christ through those He sent to instruct. If speaking truth causes anger and hostility in a heart, then that heart is not seeking Christ, the problem is not with the messenger of God, but with the rebellious heart that refuses to listen to a rebuke or correction.
When we reject the messengers of God who read the Word and speak of it and is met with rejection, then God will not speak to them personally. God speaks to those who belong to Him and they know Him when He does.
John 10:27-28 "My sheep hear my voice, and I know them, and they follow me. I give them eternal life, and they will never perish, and no one will snatch them out of my hand."
Hebrews 4:12 "For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart."
Luke 6:46 "“Why do you call me ‘Lord, Lord,’ and not do what I tell you?"
1 John 1:3 "That which we have seen and heard we proclaim also to you, so that you too may have fellowship with us; and indeed our fellowship is with the Father and with his Son Jesus Christ."
Romans 8:7 "For the mind that is set on the flesh is hostile to God, for it does not submit to God's law; indeed, it cannot."
Those who have been intimidated into silence by others, walk in fear of man rather than love and fear of God. Whenever we place man above God we have an idol and that idol includes ourselves as well as other we elevate.
Proverbs 29:25 "The fear of man lays a snare, but whoever trusts in the Lord is safe."
Hebrews 13:6 "So we can confidently say, “The Lord is my helper; I will not fear; what can man do to me?”
Galatians 1:10 "For am I now seeking the approval of man, or of God? Or am I trying to please man? If I were still trying to please man, I would not be a servant of Christ."
The more time we spend with Christ and His Word in prayer, the greater discernment we develop and much less likely to fall into worldly thinking. Everything worldly we encounter will be quickly exposed through the principles of God's Word as they come to mind. The more we meditate on Christ and His Word, the greater discernment.
1 John 4:1 "Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world."
Philippians 1:9-10 "And it is my prayer that your love may abound more and more, with knowledge and all discernment, so that you may approve what is excellent, and so be pure and blameless for the day of Christ,"
Proverbs 3:1-6:35 "My son, do not forget my teaching, but let your heart keep my commandments, for length of days and years of life and peace they will add to you. Let not steadfast love and faithfulness forsake you; bind them around your neck; write them on the tablet of your heart. So you will find favor and good success in the sight of God and man. Trust in the Lord with all your heart, and do not lean on your own understanding. ..."
Proverbs 2:1-5 "My son, if you receive my words and treasure up my commandments with you, making your ear attentive to wisdom and inclining your heart to understanding; yes, if you call out for insight and raise your voice for understanding, if you seek it like silver and search for it as for hidden treasures, then you will understand the fear of the Lord and find the knowledge of God."