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.
All Commentaries on Matthew 18:19 Go To Matthew 18
John Chrysostom
AD 407
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 their own part, but He seeks for such as are like them; therefore He says of you, of the virtuous, of them that show forth an angelic rule of life. Or they pray against them that have aggrieved them, seeking for redress and vengeance; and this kind of thing is forbidden, for, Pray, says He, for your enemies. Matthew 5:44 Or having sins unrepented they ask mercy, which thing it is impossible to receive, not only if themselves ask it, but although others having much confidence towards God entreat for them, like as even Jeremiah praying for the Jews did hear, Pray not thou for this people, because I will not hear you. Jeremiah 11:14
But if all things are there, and thou ask things expedient, and contribute all your own part, and exhibit an life, and have concord and love towards your neighbor, you will obtain on your entreaty; for the Lord is loving towards man.