You said believers, mow the first thing we need to do is defined what a believer is. A believer is one who believes and loves and obeys both Jesus and His Father. Not everyone that claims the name of Christ is Christian. When you say believer, that’s too generalized, if you mean someone who believer the bible to be the infallible word of God from Genesis to Revelation even though they may not agree on certain hard to understand scripture that does not deny the blood of Christ its’ understandable that there may be some disagreement. But the discussion should be done in respect for each other.
But there is another group that claims to be believers that claim the name of Jesus and at the same time hates His Father, if one from this group is in debate with one from the group that believes the whole bible to be the word, and then these two are not both believers because they believe in two different doctrines. One believes the blood of Jesus saves, but the other believes that there’s no need of salvation, and believe Jesus is Just another good man, and not God. Now this is different than discussion of the two believers both believes the same doctrine, the doctrine of salvation is not changed.
Now when the believer and this one who claim to be Christian and deny the blood of Christ is not a believer, so the rules of debate changes, now the believer is in the presence of the enemy so he or she must stand because this opponent is out to belittle the believer, they are not looking for discussion they are looking to put down you and the blood of Christ. This discussion is not between brothers in Christ, it is between a follower of Christ and a rebel and follower of Lucifer, so this discussion will get messy because two enemies are at it’ even though the one who oppose Christ tries comes across as a believer.
Remember, there is Jesus Christ and there’s the Cosmic Christ, these two are enemies, and the person who witness the discussion between followers of the two enemies must be able distinguish between them or he will not realize that one is not a believer.