Likewise I say unto you,.... As before, in Luke 15:7
there is joy in the presence of the angels of God; who are the friends and neighbours of Christ: See Gill on Luke 15:6,
over one sinner that repenteth; which they have knowledge of, either by immediate revelation from God, or by observation in the church where they attend: the reason of this joy is, because there is one rescued out of the hands of Satan and his angels, between whom and them, there is an implacable enmity; and because another subject is added to Christ's kingdom, and by which it is enlarged, the prosperity of which they greatly desire; and because another heir is born in that family, to which they belong, and they have another social worshipper with them: and this joy is said to be "in the presence of" them; and so may design the joy of others, as of Father, Son, and Spirit, which is in their sight and knowledge; and also the joy there is among themselves.

Likewise--on the same principle.
joy, &c.--Note carefully the language here--not "joy on the part," but "joy in the presence of the angels of God." True to the idea of the parables. The Great Shepherd. The Great Owner Himself, is He whose the joy properly is over His own recovered property; but so vast and exuberant is it (Zac 8:17), that as if He could not keep it to Himself, He "calleth His friends and neighbors together"--His whole celestial family--saying, "Rejoice WITH ME, for I have found My sheep-My-piece," &c. In this sublime sense it is "joy," before "or in the presence of the angels"; they only "catch the flying joy," sharing it with Him! The application of this to the reception of those publicans and sinners that stood around our Lord is grand in the extreme: "Ye turn from these lost ones with disdain, and because I do not the same, ye murmur at it: but a very different feeling is cherished in heaven. There, the recovery of even one such outcast is watched with interest and hailed with joy; nor are they left to come home of themselves or perish; for lo! even now the great Shepherd is going after His lost sheep, and the Owner is making diligent search for the lost property; and He is finding it, too, and bringing it back with joy, and all heaven is full of it." (Let the reader mark what sublime claims Himself our Lord covertly puts in here--as if in Him they beheld, all unknown to themselves, nothing less than heaven in the habiliments of earth, the Great Shepherd above, clothed in a garment of flesh, come "to seek and to save that which was lost")!