According to the parable, unless the shepherd went after the sheep it would probably remain lost. The shepherd must take the initiative if it is to be restored to the flock and the fold. The effectiveness of salvation does not consist in our seeking for God, but in His search for us. Left to ourselves we might seek for Him throughout eternity without finding Him. Any concept that regards Christianity merely as an attempt on the part of man to find God, misses the point entirely that it is God in search of man (see on John 3:16; cf. Matt. 1:21; 2 Chron. 16:9).

 Gr. erēmos, “desert,” or “wilderness”; as an adjective erēmos means “desolate,” “solitary,” or “lonely.” The emphasis of the word is on an uninhabited region (see on ch. 1:80), hence, usually untilled or untillable land, a “waste” Hence, however, reference is made to the usual pasturelands, the hills, upland valleys, and gullies of Peraea. This “wilderness” was probably not a place of particular danger, and leaving the 99 sheep there does not imply any neglect or carelessness. In the parable as given by Matthew, the shepherd left the sheep, literally, “in the hills” (see on ch. 18:12).

 The loss of one might seem a comparatively small matter, but to the owner of the flock the loss of even one occasioned serious concern (cf. John 10:11). The Eastern shepherd commonly knew each sheep personally and cared for it not only as one of the flock but for its own sake. Not only so, but the loss of a single sheep would make an appreciable difference in his income. In the parable the fact that the sheep became lost was evidently due to its own ignorance and folly, and once lost it seemed completely helpless to find its way back. It realized that it was lost, but knew not what to do about it. The one lost sheep represents both the individual sinner and the one world that has been lost (COL 190). This parable teaches that Jesus would have died had there been but one sinner (see on John 3:16), as He did die for the one world that had sinned (see on Luke 15:7).

In the uplands of Peraea the raising of sheep was a common occupation, and upon this occasion doubtless many in the audience recalled times in which they had gone in search of lost sheep. Most of the parables Jesus told were based upon the personal experience or knowledge of His hearers (see p. 204).

In the days of Jesus this would have been considered a large flock.