Ecclesiastes 3:7

A time to rend, and a time to sew; a time to keep silence, and a time to speak;

There is a right moment to stay quiet and a right moment to speak out, and telling them apart takes wisdom and guidance from God, for staying silent is wrong when He calls for speech.
Jesus showed this by saying nothing under false accusation until He was directly questioned under authority about who He was in relation to the Father, then openly and respectfully telling the truth about Himself even though He knew it would ensure His death, thus defending His character and showing that faith must be confessed under pressure rather than denied to avoid suffering.
In helping those searching for truth, words even if true should be given only when the hearer is ready and will not be driven away, and at other times quiet restraint is wiser.
Known wrongdoing is not to be passed over in silence but named plainly, and evils that affect the whole church and endanger faith must be exposed and dealt with, while matters that would only do harm may be left unspoken.
With those newly in faith whose habits and needs still bind them, such as long use of meat, tenderness calls for withholding condemnation and speaking instead words that encourage and bless.

Timing for Silence and Speech

There is a proper time both to speak and to remain silent, and neither is right apart from its time. Wisdom is needed to discern which the moment calls for, since hunger for sympathy can press a person to speak imprudently and lay open feelings to others. The choice turns on God's direction, for when the Lord lays the command to speak, keeping silence is not fitting.

Jesus showed when each is due by holding His peace until He was directly and plainly questioned about being the Son of God. He answered only when the high priest invoked God's authority and challenged His relationship to the Father. Then He spoke openly and plainly, respectfully declaring His character and mission and affirming His relationship with God. He did so truthfully though He knew that speaking would make His death certain, rather than deny His relation to God to escape suffering and death. His answer defended His character and stands as the pattern of faithfulness under pressure, that a person when challenged must confess faith before others rather than deny it to avoid suffering or death.

Different activities likewise have their fitting times, so singing, talking, and weeping are proper at the right time but become wrong when mixed with important duties and distract from doing them. Singing itself is not wrong once the day's thinking and duties are done; what is at fault is careless singing that leads to neglect. In the same way there is a proper time to speak and a proper time to remain silent in the church, and when the burden to speak is laid on believers they should not hesitate over whether people may listen or refuse to listen. They should press the matter faithfully even if some leave the church and the truth.

Discretion in Witness and Correction

Guiding seekers of truth calls for careful judgment about timing, speaking to them at the fitting moment while recognizing when holding back is wiser. There is a proper occasion for words, and even what is true is not to be spoken at every moment, but only when the listener or patient is prepared to receive it without taking offense.

With poor families who have newly accepted faith yet remain dependent on meat because of their circumstances, the fitting course is to refrain from dwelling on the harms of meat eating. Instead of condemning and reproving, words should encourage and bless, and those long accustomed to eating meat are to be dealt with gently. In handling wrongdoing, whether to remain quiet or to speak turns on what will best correct the evil, so that harmful matters may be kept private. Yet when errors spread through the whole church and endanger faith and exert influence over others, they must be exposed and dealt with openly. Known sin is not to be passed over in silence but is to be identified plainly, while words are to be withheld when they would serve to oppress people.

Silence remains appropriate until a spirit of fault-finding, dissatisfaction, jealousy, and unbelief shows itself, and once that spirit appears it is to be met firmly and allowed no room. Wisdom is required to discern which response the moment demands, since craving sympathy can push a person to talk rashly and lay open inner feelings to others. When denouncing a wrong act aloud would accomplish no good, or when kind words toward those causing injury would only provoke harsh retaliation, remaining quiet is best. At such times keeping still becomes a source of strength.