In mainline Protestantism, people agree on a few basics, and are free to use their own conscience and reasoning to determine what they will believe and are free to change their minds on something whenever they want. Even if a person disagrees with the basics, I haven’t seen people bat an eyebrow.
For instance, in one church, I’ve seen people who believe in Trinity and those who don’t. Those who believe the Holy Spirit is a person and those who believe Holy Spirit is a “divine energy”. There are those who believe in universal salvation and those who don’t. Those who believe in preterism and those who believe in futurism. Millenniumism and amillenniumism. People are basically free to express themselves. No arguments erupt.
In fact, people can unite without having to agree on everything or to be told what they are supposed to believe. I’ve learned true unity doesn’t mean everyone has to be on the same page. Unity and freedom are not mutually exclusive.