I'm a non-denominational protestant, but my family is good friends with a Roman Catholic family down the street... we do have so much in common with them, despite our disagreement as to whether justification and righteousness before God is conferred on the basis of faith alone in Jesus Christ alone.
There is a strong tendency for Catholics and Protestants, when we all chill out and sit down carefully making distinctions about Justification, to find we agreed all along but had different language to describe the same thing.[1] I suspect it extends to other doctrinal issues and areas of genuine disagreement become much more productive when said attitudes and practices are adopted.
I also strongly suspect that most areas of disagreement between Christians are persistent symptoms of European Renaissance politics with theological rationalization.
[1] https://en.m.wikipedia.org/wiki/Joint_Declaration_on_the_Doc...
Speaking more seriously, most churches these days are very ecumenical since they have realized they have much more in common with each other than secular culture.