Wednesday, 19th Week in Ordinary Time
From: Matthew 18:15-20
Fraternal Correction. The Apostles' Authority
(Jesus said to His disciples),  "If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother.  But if he does not listen, take one or two others along with you, that every word may be confirmed by the evidence of two or three witnesses.  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.  Truly, I say to you, whatever you bind on earth shall be bound in Heaven, and whatever you loose on earth shall be loosed in Heaven.  Again I say to you, if two of you agree on earth about anything they ask, it shall be done for them by My Father in Heaven.  For where two or three are gathered in My name, there am I in the midst of them."
15-17. Here our Lord calls on us to work with Him for the sanctification of others by means of fraternal correction, which is one of the ways we can do so. He speaks as sternly about the sin of omission as He did about that of scandal (cf. Chrysostom, "Hom. on St. Matthew", 61).
There is an obligation on us to correct others. Our Lord identifies three stages in correction: 1) alone; 2) in the presence of one or two witnesses; and 3) before the Church. The first stage refers to giving scandal and to secret or private sins; here correction should be given privately, just to the person himself, to avoid unnecessarily publicizing a private matter and also to avoid hurting the person and to make it easier for him to mend his ways. If this correction does not have the desired effect, and the matter is a serious one, resort should be had to the second stage--looking for one or two friends, in case they have more influence on him. The last stage is formal judicial correction by reference to the Church authorities. If a sinner does not accept this correction, he should be excommunicated that is, separated from communion with the Church and Sacraments.
18. This verse needs to be understood in connection with the authority previously promised to Peter (cf. Matthew 16:13-19): it is the hierarchy of the Church that exercises this power given by Christ to Peter, to the Apostles and their lawful successors--the Pope and the Bishops.
19-20. "Ubi caritas et amor, Deus ibi est: where charity and love resides, there God is", the Holy Thursday liturgy intones, drawing its inspiration from the sacred text of 1 John 4:12. For it is true that love is inconceivable if there is only one person: it implies the presence of two or more (cf. Aquinas, "Commentary on St. Matthew", 18:19-20). And so it is that when Christians meet together in the name of Christ for the purpose of prayer, our Lord is present among them, pleased to listen to the unanimous prayer of His disciples: "All those with one accord devoted themselves to prayer, together with the women and Mary the mother of Jesus" (Acts 1:14). This is why the Church from the very beginning has practiced communal prayer (cf. Acts 12:5). There are religious practices--few, short, daily "that have always been lived in Christian families and which I think are marvelous--grace at meals, morning and night prayers, the family rosary (even though nowadays this devotion to our Lady has been criticized by some people). Customs vary from place to place, but I think one should always encourage some acts of piety which the family can do together in a simple and natural fashion" ([St] J. Escriva, "Conversations", 103).
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.