Διὸ ἀποθέμενοι τὸ ψεῦδος λαλεῖτε ἀλήθειαν ἕκαστος μετὰ τοῦ πλησίον αὐτοῦ ὅτι ἐσμὲν ἀλλήλων μέλη. Therefore, putting aside falsehood, every one speak truth with his neighbor, for we are part of one another.
In this sentence, Paul concludes his previous discussion of the new person from the previous sentence. To sum up what he has been arguing regarding this new person, he exhorts his readers and listeners to speak the truth after putting away falsehood. The participle ἀποθέμενοι is temporal. It is antecedent to λαλεῖτε. After putting off falsehood, meaning, after getting rid of falsehood, every one, every person is to speak truth with his neighbor. The imperative is linked together with ἕκαστος to form what seems to be an idiomatic phrase: let each person speak. The force of this clause is still a command despite the use of the word “let” in the translation.
And who is our neighbor? A neighbor in our minds is a person that lives next-door; but this word, τοῦ πλησίον, has the idea of a fellow-human being. However, in this context, Paul has in mind fellow-Christians, as is evident with the next clause: “for,” he continues, “we are a part of one another.” In other words, Paul has in mind the Church, of which individual Christians are all members. Christians are exhorted to speak truthfully with each other, because they are all part of the same group that is supposed to be characterized by truthfulness.
Therefore, after getting rid of falsehood, let each person speak the truth with his neighbor, for we are part of one another.
Speaking the truth can be hard sometimes. If you ever find yourself in a situation where the truth would be harmful to someone else, it may come across your mind to lie. Should you? I think, since we are part of a group that is to be characterized by the truth, we should speak the truth as often as we are able. But in those moments, and they do occur, where we should refrain from speaking the truth, I think we should not lie, but refrain from speaking altogether. Will this apply to every situation life can present? Certainly not. But in general, I think it is a good practice to refrain from speaking when it might be a good idea to not tell the truth. I suppose one would, in such instances, “plead the fifth.” But in no circumstance should we be characterizing ourselves with lying. We are to be people of truth and holiness. Part of being holy is being separate; telling the truth (or pleading the fifth, which can still result in some penalties at times) instead of telling a lie is not always easy, and when we do it when it hurts, especially when it hurts, we are not only being characterized by the truth, but also by holiness, thus fulfilling the intention that God has for us.