Some very general rules about relationships and communication: something which is far easier to understand than it is follow:
First, there is the matter of communication. It is to be clear and direct, not manipulative. That is what Jesus meant by “let your yes be yes”; and what is behind the command in Matthew and James against swearing:
The theme of greater righteousness continues, but Jesus’ examples move outside the Decalogue. As with his teaching on divorce, he again forbids what the Old Testament permitted. “Do not break your oath” alludes to Lev 19:12 and Num 30:2 and would more commonly be translated “do not swear falsely” or “do not perjure yourself.” To “swear” (v. 34) does not mean to curse or use bad words but to affirm the truth of a statement while calling on God to judge oneself if it is in fact untrue. Again qualifications are implicit. There are oaths which are consistent with God’s character and demands even in the New Testament (e.g., 2 Cor 1:18; Gal 1:20), but given the casuistry (an elaborate hierarchy of laws) of first-century Judaism on oaths (cf. the entire Mishnaic tractate Shebuoth), Jesus declares that it would be best to avoid them altogether. The situation described is one in which many Jews viewed swearing by “heaven,” “earth,” “Jerusalem,” or “one’s head” as less binding than swearing “by God.” Jesus stresses that each of these items belongs to God in an important way (cf. Isa 66:1) so that the conventional Jewish distinctions are spurious. Even one’s head, which might be thought to be uniquely under an individual’s control, has divinely predetermined features, such as hair coloring (temporary dyeing is not in view here!). Rather, Jesus’ followers should be people whose words are so characterized by integrity that others need no formal assurance of their truthfulness in order to trust them.
Craig Blomberg, Matthew, vol. 22, The New American Commentary (Nashville: Broadman & Holman Publishers, 1992), 112.
Communication is to be timely, build up the other (edify), and gives grace. Eph. 4:29
We will be judged for every careless word. Matt. 12:36
Second, there is general matter of behavior. Put simply we must act in a way which makes it easy for the other person to act properly before God and man.
The marriage relationship as the most basic (Gen. 2) and intimate, contains some basic elements of relationship which will be illustrative of other relationships.
For example: If a wife respects her husband, it makes easy for him to love her. If a husband loves his wife, it makes it easy for him to respect her. The duty of each is independent of what their spouse does (your bad behavior doesn’t excuse my sin): but if I make it hard you to be holy, if I tempt you to sin by my behavior, I am responsible for that also. It is causing a little one to stumble.
Phil. 2:3 Do not act in a way to promote yourself at the expense of others. Instead begin with humility and consider the other person as more important than me.
These basic elements of love, respect, humility are intrinsic to all relationships: even relationship of authority:
24 And when the ten heard it, they were indignant at the two brothers. 25 But Jesus called them to him and said, “You know that the rulers of the Gentiles lord it over them, and their great ones exercise authority over them.26 It shall not be so among you. But whoever would be great among you must be your servant,27 and whoever would be first among you must be your slave,28 even as the Son of Man came not to be served but to serve, and to give his life as a ransom for many.”
The difficulty: These commands are difficult to fulfill, because our emotions get in the way. It will often cross our own desires and fears to do this.
First, the other person does not “deserve” this conduct. Kirkegaard gave a good illustration here. If I loan someone money, I can require that they repay that money by giving it to someone other than me. God has a right to make any demand upon us. He has the right to require that we show love to others who do not deserve it.
Second, we may not get what we want from the relationship. Again, we need to understand in relationship to God. We are not supposed to think of other persons as resources. We do not have the right to expect other people to do anything for us or to reward us. We are to do what God requires and look to God for the reward.
Third, we are afraid we will be hurt. Again, our task is to do what God commands to leave the result to God.
On this point: it is the case that when both parties do what they are required to do in relationships, we both get what we desire. We want the other person to show us love and respect; we get that by first showing love and respect.
This is very, very hard to do. And the more we do the opposite, the harder it becomes.