From Matthew 18 NKJV
15 “Moreover if your brother sins against you, go and tell him his fault between you and him alone. If he hears you, you have gained your brother. 16 But if he will not hear, take with you one or two more, that ‘by the mouth of two or three witnesses every word may be established.’17 And if he refuses to hear them, tell it to the church. But if he refuses even to hear the church, let him be to you like a heathen and a tax collector.
From 1 Timothy 5 NKJV
17 Let the elders who rule well be counted worthy of double honor, especially those who labor in the word and doctrine. 18 For the Scripture says, “You shall not muzzle an ox while it treads out the grain,” and, “The laborer is worthy of his wages.”19 Do not receive an accusation against an elder except from two or three witnesses. 20 Those who are sinning rebuke in the presence of all, that the rest also may fear.