Gentleness & Manipulation
There are many articles that talk about politeness in a similar context.
Do not quarrel about words, but focus on the spirit of the law.
Ultimately, those who are disagreeable love controversy because they quarrel on the words of the law over seeking unity (Proverbs 20:3), also known as being legalistic. This conceit leads to slandering the character of others, causing dissensions (I Timothy 6:4). They intend for this behavior to save their friends from following false teachers but in reality, it only causes them to become evil like them (II Timothy 2:14). Rather, we are now free of the written code (Romans 7:6) to pursue the law that is now written on our hearts (II Corinthians 3:3). God wants us to pursue holiness by loving God from our hearts and not our understanding (Proverbs 3:5-6). When we debate, we must focus on what each person is trying to say about the core nature of righteousness, not debating little errors in arguments, like false teachers (I Timothy 6:3,4).
Compassionately ask if you understand them.
If you plan on teaching someone, make sure you understand them first (I Timothy 1:7), for the arrogant believe they know everything (Proverbs 18:2; I Corinthians 8:2). Compassion is understanding the source of their pain (Matthew 9:36; Mark 8:2) before you rebuke them.
Start on common ground.
Our primitive brains tend towards animalistic tribalism because we are naturally afraid of dying (Matthew 10:28). Why is disagreement so painful? We think we’re good, so the disagreer must be like Satan, who wants to kill me (John 10:10). Instead, we should start with commonality (Acts 17:22,23). What many Christians unfortunately do is go up to someone, and say, “You are wrong because…,” but that only puts up a wall of mental separation. Instead, you should go up to him with, “We do agree on this point…” This showing of common ground will put him at ease that you don’t want to destroy him (I Corinthians 8:10-11), just his beliefs (II Corinthians 10:5).
Being disagreeable is inefficient.
Being disagreeable wastes words and time. It adds no logic to the conversation; see an example:
Option A: “What you were saying was taken completely out of context! I think you are misrepresenting our agreement, as I strongly disagree with you that I owe you $500 because I paid that in January.”
Option B: “I have already paid my $500 debt in January.”
Being disagreeable enhances unhealthy emotion.
Logically, by stating one’s personal opinions with the truth, you will focus on the opinion as much as the truth. Saying you disagree is just your opinion, and opinions don’t mean much, but stating the truth is quoting the Bible and Jesus, which means everything (John 14:6). Unless it’s to clarify your interpretation of Scripture, it’s best to leave your opinions out of a debate (Proverbs 29:11).