Therefore, since we put on a new self in Christ and reject our natural entitled and self-absorbed ways, we lay aside falsehood and speak the truth to one another. The practice of falsehood is a selfish practice. We lie because we don’t want to be found out. We pretend to be righteous because we want to appear to be better than others. We wear masks and call it holy. But, we are members of one another—so we do not bear false witness about ourselves or one another within the body of Christ.
When we get angry, which itself is not inherently a sin, we do not sin in that anger. Even in our anger, we are interested in restoration rather than retaliation. We seek to restore relationships before the day is over instead of letting any anger or frustration fester. There are things we should be angry about, but I am convinced that, in most cases, we become angry because of our natural selfishness. We resolve it by putting on the new self in Christ. In rejecting the sin that results from our natural anger, we do not give the devil an opportunity to affect others through us.
When a thief comes to Christ, he forsakes his theivery and learns how to labor, working in a way that is good so he will have something to give away to others. Instead of continuing in his entitlement, he puts off the old self and puts on the new self in Christ.
Though, in our natural bodies, we spoke in unwholesome ways, we no longer speak unwholesome speech. Paul juxtaposes unwholesome speech with edifying speech, here. To speak unwholesome words doesn’t here deal specifically with cussing, though many people water this verse down to mean refusing a few four-letter words. Here, Paul instructs us to be careful of our language such that others are built up by it and not a word is spoken in vain or to tear others down. So, many people who abstain from cuss words sin because they still thrash others with their words of judgmentalism and hatred. They look down their noses at others instead of edifying them. But, we have put off the old self that needs to treat others so terribly. We speak in ways that are edifying. In our speech, grace is given to those who hear.
We are instructed not to grieve the Holy Spirit, namely by being selfish (especially in our interactions with others). We have been sealed by the Holy Spirit for the day of redemption. At our respective conversions we are sealed as the property of Christ and receive the Holy Spirit. On the day of redemption, we will be fully delivered from the old self. Until that day, we work out our salvation in sanctification. We let all, yes all, bitterness, wrath, anger, clamor, slander, and malice be put away from us. That is the way of the old man, not the new in Christ. Instead, we are kind, tender-hearted, and forgiving of one another. Why? These are how Christ is toward us. Those who have been forgiven much love much (cf. Luke 7:47).