Matthew 18 can be a tricky chapter. Jesus begins by saying that the greatest in the kingdom must become like little children. Then he says that it would be better for someone who causes any of the little ones to suffer to have a large millstone tied around his neck and to be drowned in the depth of the sea.
Then Jesus goes into a discourse on the necessity for mercy. He tells the parable of the lost sheep, followed by a story about the brother who sins against his other brother. He says if that brother sins against you, go and show him his fault. If he listens, you have won your brother over. But if he refuses, you should take one or two others along with you. If he still refuses, the brother is to be brought before the church.
Then Jesus tells them, “Again I say to you, if two of you agree on earth about anything they ask, it will be done for them by my father in heaven. For where two or three are gathered in my name, there am I among them” (Matthew 18:19, 20 ESV). This verse has been used out of context to “prove” that it’s only necessary for two or three people to be present to worship God. But that is far from the point of the passage. The point is that there is power in the witness of two or more people. Whether we are disciplining, worshiping, or praying, there is power when two or three gather.
This is important for those of us who pray for others. James says that the prayer of a righteous person is powerful and effective. Christians need to work together, not isolated from one another. When we work together God is present and powerful!