The Lord has made us one, yet the older I get, I find us who are in Christ are no less immune to the “us against them” mentality – I am not talking about the “us against the world” mentality (which is equally toxic), but the “us against them” within the Church itself.
We often form judgment and cliques based on our suspicions, our insecurity, the flaws that we see in others (while not seeing our own), theological differences, and so on. We feel great when we are “not like those…”
But “those” people are a part of you. Those people are a part of Christ.
It is easy to become a pharisee standing on a higher ground.
One way that helps may be to substitute the “they”with “we”. Take the simplest example: if you find yourself being temped to say, “Those Christians don’t understand the gospel”, turn it into perhaps something like this, “May we all understand the gospel. Lord, help us to cherish the gospel so that we can love You and others even more.” Amen.