Who is wise and understanding among you? He should show his works by good conduct with wisdom’s gentleness. But if you have bitter envy and selfish ambition in your heart, don’t brag and lie in defiance of the truth. Such wisdom does not come down from above, but is earthly, sensual, demonic. For where envy and selfish ambition exist, there is disorder and every kind of evil. But the wisdom from above is first pure, then peace-loving, gentle, compliant, full of mercy and good fruits, without favoritism and hypocrisy. And the fruit of righteousness is sown in peace by those who make peace.
(James 3:13-18 from Holman Christian Standard Bible® Holman Bible Publishers.)
If you find it difficult to let people finish their sentences, you may be suffering from a selfish condition. Interrupting people when you disagree with them is not always “defending the faith.” Sometimes it is just being fearful. If I know the truth, and your speech exposes the fact that you don’t, I may not help you by correcting you.
We have to be born of God to see the Kingdom (John 3:3). We have to be spiritually minded to receive spiritual communication from the Spirit (1 Corinthians 3:1). If I have a spiritual word to deliver to you, it will be good for you if I wait until you are spiritually minded before I try to deliver it to you, or you will not be able to discern the truth in it.
I am dishonoring your right to have an opinion if I interrupt you with corrections constantly. I am preferring being right or being known for being right perhaps. If I want everyone to know that I knew “that” before you did, my ambition is selfish. Ambition is not evil. Selfish ambition opens doors to enemies, though.
When Jesus encountered the disciples’ argument in Luke 9:46 about which of them was the greatest, He didn’t rebuke them for having ambition to be the greatest. He taught them the different values set of greatness in the place where He is King: simply be like a child – no rights, no voice, nothing but dependence and servitude – and you will be the greatest in the crowd.
Let people talk. Even if they are not right. Ask the Spirit whether to speak or wait. Love them deeply and patiently. Exercise generous ambition.
Besides, people love it so much when you bless them by listening to them, sometimes they actually pay you the honor of wanting to hear what you have to say. Then you can say anything.