18:17 church. The use of the word “church” by Jesus may appear premature, but only if the “church” is divorced from its moorings in the Old Testament. In the Greek translation of the Old Testament (the Septuagint), the “assembly” of the people of God is called the ekklesia, or “church.” Jesus’ use of Deut. 19:15 in v. 16 implies that the church is equivalent to Old Testament Israel.
let him be to you as a Gentile and a tax collector. Such individuals are to be cut off from fellowship and suspended from full social relations with other Christians. Paul applies this discipline in 1 Cor. 5 and 1 Tim. 1:20.