Matthew 18:15-20 15 “If your brother sins, go and show him his fault in private; if he listens to you, you have won your brother.16 But if he does not listen to you, take one or two more with you, so that BY THE MOUTH OF TWO OR THREE WITNESSES EVERY FACT MAY BE CONFIRMED.17 If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector.18 Truly I say to you, whatever you bind on earth shall have been bound in heaven; and whatever you loose on earth shall have been loosed in heaven.19 “Again I say to you, that if two of you agree on earth about anything that they may ask, it shall be done for them by My Father who is in heaven.20 For where two or three have gathered together in My name, I am there in their midst.”
I read in a post on the board today a snip of this passage, "where two or three are gathered in my name". This is one of the most misapplied portions of scripture in the entire bible. It is often used to say that where two are three are gathered [in prayer], God is in the midst. If that was true than God would not be present if one or four are gathered in His name. The passage has nothing to do with the gathering of the church/believers for worship, prayer, or fellowship. The passage is referring specifically, and exclusively, to church discipline.
Jesus is explaining how to deal with a brother who sins. He goes through the process of showing the brother his fault in private. If the brother refuses to repent the process is escalated, all they way up to, and including, excommunication. Jesus underscores the need for truthful witnesses in the process, so He states that charges need to be confirmed by two or three witnesses (v. 16). He repeats Himself in verse 19 by saying, "Again, I say to you...".
Now, it is true that Jesus is present, through the Holy Spirit, if two or three are gathered. But He is also present if one, twelve, or three hundred and eighty five are gathered.