Again I say unto you, That if two of you shall agree on earth concerning anything that they shall ask, it shall be done for them of my Father who is in heaven.
Read Chapter 18
Chromatius of Aquileia
AD 407
How important a place the unanimity and harmony of brothers hold with God! We can know from this very fact that the Lord has clearly said that when two or three pray in unanimity, the Father grants everything from heaven. For with God nothing is more pleasing than brotherly peace, nothing better than unanimity and harmony, according to what is written: “Behold, how good and pleasant it is when brothers dwell in unity. And again: “There is great peace among those who love your name, and there is no stumbling block for them.” And in another place: “The God who makes us live in harmony in the house.” So Isaiah also testified: “Lord,” he said, “our God, give us peace. For you have given us everything.” That this harmony of brothers is pleasing to God, the Holy Spirit declared through Solomon, saying, “There are three things which are pleasing to God and men: harmony of brothers, love of one’s neighbors and the union of man and woman.” So quite rightly the Lord in this passage testifies tha...
That if two of you: From these words, we learn how superior is public to private prayer. The efficacy of the former is attributed to the presence of Christ in those assemblies. The Father, for his Son's sake, will grant petitions thus offered. (Jansenius)
The fervour of one will supply for the weakness and distractions of the other.
Do you see how by another motive also He puts down our enmities, and takes away our petty dissensions, and draws us one to another, and this not from the punishment only which has been mentioned, but also from the good things which spring from charity? For having denounced those threats against contentiousness, He puts here the great rewards of concord, if at least they who are of one accord do even prevail with the Father, as touching the things they ask, and have Christ in the midst of them.
Are there then indeed nowhere two of one accord? Nay, in many places, perchance even everywhere. How then do they not obtain all things? Because many are causes of their failing. For either they often ask things inexpedient. And why do you marvel, if this is the case with some others, whereas it was so even with Paul, when he heard, My grace is sufficient for you; for my strength is perfected in weakness. Or they are unworthy to be reckoned with them that heard these words, and contribute not ...