In Matthew 18:19, 2019Again I say unto you, That if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven. 20For where two or three are gathered together in my name, there am I in the midst of them. (Matthew 18:19‑20) it is assembly prayer, and two agree to ask of the Father in Christ’s name, and the Father gives, because they not only ask in Christ’s name, but they are also gathered together unto His name, and He is in the midst. The point is, that it is because Christ has taken His place in the midst of those thus gathered, that the Father answers such prayer.
Individuals praying in Christ’s name have their prayers answered according to John; but here it is gathered ones. The word “For” at the beginning of verse 20 connects it with verse 19.
To illustrate, look at Matthew chapter 3 where the Lord takes his place with the repentant ones, and sanctions their act by His presence amongst them, and by being baptized too. Immediately the Father shows His approval of Christ’s act, by saying He was His Son, and that He was well pleased with Him, at the same time showing that Christ was personally apart from them, and had no sin to confess.
So it is in this chapter, the Father answers the prayers of the gathered ones, because Christ is in the midst. It is really an answer to Christ, as having identified Himself with us, so that every time the Father answers our requests in this way, He glorifies Christ, bearing witness to the place Christ has taken in the midst.
How much we lose when we neglect this privilege, and also how much He loses when we do not give him the opportunity to take that place, and receive testimony from the Father to His condescension and grace in being there.