Jesus said the world would know that we are his disciples by the love we have for one another. One good way of overcoming a tendency to be critical of other Christians is to reject the idea that the visible church is the real one. Names on church buildings mean little. (“They are not all Israel that are [descendants] of Israel, but in Isaac shall your seed be called.”)
When we criticize others we are no different from those raw believers in the church at Corinth who said: “I am of Paul; I am of Apollos” and other leaders. Jesus did not say that it would be by our love for God, or even for him, that the world would know that we are his disciples, but rather by our love for one another. Not just for those we identify as from our own denominational encampments
Sparks are bound to fly between Brother Black and Brother Smith, but in the process they’ll sharpen one another. And over time, scratchy Sister Sandpaper may smooth out some splintered relationships. Most dust raised settles before long when left alone.
Whichever metaphor you prefer, they all mean that being a Christian means loving one another; meaning those we may think unlovely, as well as — maybe even as much as — those we’ve found easier to like.
One man told me years ago that he chose not to come to our church because there were people in it he didn’t like. “I think that’s a good idea,” was my response.
“Why?” he asked, more than a little surprised. I said, “Because if you came, there’d likely be some who don’t much like you and so would leave.” I was kidding, of course, but my comment shocked him. It also changed his attitude to the point that he came back to church (where he was received by everyone as well as he had been before leaving).
When speaking words that ‘go against the grain’ in the minds of others, we can do surface damage to usually good relationships, much in the way we would if we tried to plane a length of wood against its natural grain. We need to learn how to ‘smooth’ relationships by not just showing other Christians where we think they are wrong but how they can do things better by doing them God’s way.