We can underestimate the power of the tongue. Speech has the power to harm as well as do good.
Do not underestimate the difficulty of taking the tongue. The tongue was made to praise God. We must also be mindful to not devalue other people, as we are all made in the image of God.
Do not underestimate the power of Satan to twist our words. Is our counsel in alignment with God's Word or are our good intentions corrupted by evil?
A "speech problem" is due to a "heart problem". Those who teach must be aware of their influence and the responsibility they bear. They will be held accountable.
We all stumble and hurt others, but remember that Jesus came to save sinners. Repent and seek forgiveness and going forward we must seek to speak the truth in love.