Though it is God who cleanses us from all sin, our responsibility is not negated. We pray for God to change us and he will point out those areas that need changing. He may also arrange circumstances so that your desire to change will be increased. But he gives us the responsibility to actively decide to change (Colossians 3:8).
We are responsible to stop being angry people. We are responsible to stop spewing out our wrath as though we were the rulers of men and not God. We are to stop using filthy language. We are responsible to clean up our act.
In the middle of the lists of behaviors we are to change, the author of Colossians includes the word, blasphemy. What believer would purposefully utter blasphemy?
The author is connecting blasphemy with anger, wrath and malice. When we become angry that others don’t do what we want them to, we have placed ourselves on the level of God. We are behaving as though we are completely righteous and therefore have the ability to judge others righteously without error. This is blasphemy because God is the only righteous judge (Mathew 7:1-5; Romans14:4).