Jesus spoke of His followers as sheep. Why would Jesus compare us to the dumbest animal? A cat, a dog, a cow, a horse… all of these can find their way home. A sheep, however, will be lost even though it may not be far from its pasture. It will continue to stray not knowing where it is going.
I guess the Lord knew how fickle human nature is. The real truth presented by this is that we have a Shepherd. He is constantly alerted when we stray and is there to bring us back. All of us have been in that situation, some farther away than others, but He loves His sheep and will leave the 99 in the fold while He searches for one sheep gone astray.
BLESSED ASSURANCE DAILY DEVOTIONS 