It is not the loudness of shouting that makes verbal abuse unacceptable in the workplace, but its extraordinary capacity to disable. The old English saying, "Sticks and stones may break my bones but words will never hurt me", is rubbish.  Words are divinely designed to have a powerful effect.  For example: God spoke into nothing and the universe came into being (Genesis 1:1).  Confession mixed with faith in Christ brings forgiveness (1 John 1:9), and words of blessing are honoured by God (Numbers 6:24); likewise, words of cursing or anger are not just psychologically inconvenient - they allow evil to operate (Ephesians 4:26-27).

The catalogue of spoken violence, in these verses, is clearly out of order for Christians, in the church or anywhere else.  Yet the Apostle's command indicates that Christians were indulging in these habits.  However common they were in their society, they had to be eliminated from the believers' mouth-style.  Malicious speech needed to be replaced, not just by nice talk; a whole new attitude was needed.  The mouth simply reveals what is in the heart (Matthew 15:19).  So, to eliminate the hateful talk needs a major change in the heart.  

The starting point for such a change is the reminder that God has the power to forgive, wants to forgive and does forgive all who repent of what is wrong (Ezekiel 18:31).  He wants to give us a new heart (Ezekiel 36:26).  If anybody is in Christ, they are a new creation (2 Corinthians 5:17) and so we should practise what we are.  The instruction to change our verbal behaviour is about recognising what is wrong, confessing it, receiving forgiveness and then learning to live with a new mouth.  For many, it is a foul-mouth habit which needs to be broken; for others it is recognising that stress is not an excuse for verbal violence.  When we know the truth then we can work with the Lord to change.

We cannot put a veneer of compassion and forgiveness over a malicious heart; at least, not with any degree of integrity. Our minds need to engage with the need to put others before ourselves, as Christ did for us.  Then, practise this new attitude with others in your local church.  After that, you are ready to go to work!  Understanding what needs to be discarded (and why), you can start to live the transformed mouth-style which will be so appreciated wherever you work.  And people will notice the positive difference.  When they comment about the change, you can tell them the story: some will want to join you.