I say unto you, that likewise joy shall be in heaven over one sinner that repenteth, more than over ninety and nine just persons, which need no repentance.

People's New Testament

15:7 Joy shall be in heaven. The Father rejoices and the Son and the angels with him.

Over one sinner that repenteth. That comes to himself, decides to leave off sin and to serve God. Repentance means a change of mind or heart.

Than over ninety and nine righteous persons. Over those who are already in Christ, safe, and need no repentance. It is the saving of the lost that brings the greatest joy.

Wesley's Notes

15:7 Joy shall be - Solemn and festal joy, in heaven - First, in our blessed Lord himself, and then among the angels and spirits of just men, perhaps informed thereof by God himself, or by the angels who ministered to them. Over one sinner - One gross, open, notorious sinner, that repenteth - That is, thoroughly changed in heart and life; more than over ninety and nine just persons - Comparatively just, outwardly blameless: that need not such a repentance - For they need not, cannot repent of the sins which they never committed. The sum is, as a father peculiarly rejoices when an extravagant child, supposed to be utterly lost, comes to a thorough sense of his duty; or as any other person who has recovered what he had given up for gone, has a more sensible satisfaction in it, than in several other things equally valuable, but not in such danger: so do the angels in heaven peculiarly rejoice in the conversion of the most abandoned sinners. Yea, and God himself so readily forgives and receives them, that he may be represented as having part in the joy.

Jamieson-Fausset-Brown Bible Commentary

7. ninety-nine just . needing no repentance-not angels, whose place in these parables is very different from this; but those represented by the prodigal's well-behaved brother, who have "served their Father" many years and not at any time transgressed His commandment (in the outrageous sense of the prodigal). (See on [1674]Lu 15:29; [1675]Lu 15:31). In other words, such as have grown up from childhood in the fear of God and as the sheep of His pasture. Our Lord does not say "the Pharisees and scribes" were such; but as there was undoubtedly such a class, while "the publicans and sinners" were confessedly the strayed sheep and the prodigal children, He leaves them to fill up the place of the other class, if they could.

Matthew Henry's Concise Commentary

15:1-10 The parable of the lost sheep is very applicable to the great work of man's redemption. The lost sheep represents the sinner as departed from God, and exposed to certain ruin if not brought back to him, yet not desirous to return. Christ is earnest in bringing sinners home. In the parable of the lost piece of silver, that which is lost, is one piece, of small value compared with the rest. Yet the woman seeks diligently till she finds it. This represents the various means and methods God makes use of to bring lost souls home to himself, and the Saviour's joy on their return to him. How careful then should we be that our repentance is unto salvation!