We need not have a temper when we are trusting Christ.
Temper is associated with anger about not getting our way or about others not treating us the way we wish to be treated, it is deeply connected to pride.
If we are not concerned about what people think of us we will not be angry when they mistreat us.
If we trust Christ and know that He directs everything on our behalf for our good we need not be upset when things do not go our way or when people abuse us.
God brings peace within our souls if we want it. We can remain calm and peaceful no matter what is happening to us.
Our souls can be peaceful and full of joy even when we are abused by others. Yes, we cry out to God, we are in distress but it does not drive us to do evil to others.
Luke 6:27-28 "27 But to those of you who will listen, I say: Love your enemies, do good to those who hate you, 28 bless those who curse you, pray for those who mistreat you."
John 14:27. "Peace I leave with you; my peace I give to you. Not as the world gives do I give to you. Let not your hearts be troubled, neither let them be afraid."
The world will not be at peace all around us but our inner heart, our soul will have peace.