A disagreement should not require rewriting someone’s entire character.

It is possible to think someone is mistaken about one thing without reclassifying them as a bad person. The slide from this is wrong to you are wrong to you have always been like this happens fast and it makes anything hard to discuss, because now the whole person is on trial.

Keep the disagreement the size it actually is. One issue, this instance, this decision. That restraint is what makes it possible to disagree with someone repeatedly and still be close to them.