Why does the Bible refer to believers as sheep? Why not eagles, falcons, lions or tigers?
The Nature of Sheep
My uncle in Iowa used to raise sheep, and I can remember him saying a lot of things about his sheep; most of it bad. For example, they would not come near us; my brother and I tried riding one…not a good idea. For one thing, sheep are defenseless against predators. They’re afraid of moving water, and can only be led to still water by a shepherd (Psalm 23:2). They are especially afraid of strangers. That’s because they don’t know their voice. They only know the shepherd’s voice…even in the dark. Sheep can’t swim very well and for very long, and can drown easily enough. They can even be frightened into having a heart attack, sometimes by lightning. Sheep are not that smartest of animals either. If left alone, they’ll eat the grass right down to the roots, destroying the pasture, unless the shepherd moves them. And sheep can become grimy, dirty, smelly, and filled with vermin. In summary, sheep can’t run fast with short legs…they can’t outrun any predators at all, and they’re basically defenseless because they can’t bite back. Flight or fight won’t work for them because they have no natural defenses. They are the most vulnerable of all animal species. And maybe that’s Jesus’ point in the Parable of the Good Shepherd, but we’re getting ahead of ourselves.
Need for the Shepherd
One reason sheep are vulnerable is because they are directionless without a shepherd, and more importantly, the shepherd cannot protect sheep that are not in his fold. Neglected sheep are more susceptible to predators, and in similar fashion, neglected sheep in the church are susceptible to false teachers. They must be fed the whole counsel of God; the whole Word of God. Sheep, without a true shepherd, are more prone to follow wolves in sheep’s clothing teachings, especially if they neglect to hear the Shepherd’s voice, meaning the Word of God (John 1). Still need more evidence that sheep are hopeless without a shepherd? For one thing, sheep have been known to just walk right off a cliff. Not long ago, 200 sheep died in a drenching rain storm in Ireland where hundreds huddled together and many on the bottom of the pile were drowned or smothered. In Turkey, hundreds of sheep followed their shepherd off a cliff when he tried to rescue a lamb too close to the edge. He slipped and fell, but held on, but hundreds of sheep followed their shepherd off the cliff, plunging to their deaths. In Iran, one sheep wandered off a cliff, and 1,499 others just followed right along. Can you picture that…1,500 sheep, each walking off a cliff, one at a time!? Some survived, but they were piled so deep that the ones at the bottom were crushed to death or smothered by the ones on top. To be honest, if we look around the animal kingdom, sheep may be the dumbest of all animals. I know that’s not very flattering when God describes us as His sheep or like sheep…but that’s the point! It should humble us. We have no reason to boast (1 Cor 4:7). All glory goes to the Good Shepherd (Psalm 115:1)! The sheep are utterly dependent their shepherd, just as we are fully dependent upon the Good Shepherd, Jesus Christ.
The Good Shepherd
Astonishingly, sheep are silent while being sheared or while being led to the slaughter (due to fear or submission, I don’t know.), but so was Christ at Calvary. The Apostle Peter, an eye witness to Jesus’ suffering, wrote, “When he was reviled, he did not revile in return; when he suffered, he did not threaten, but continued entrusting himself to him who judges justly” (1 Pet 2:23). The thief on the cross knew enough to say that “we indeed justly, for we are receiving the due reward of our deeds; but this man has done nothing wrong” (Luke 23:41), so it took the sinless’ life, death, and resurrection of Jesus Christ to make our salvation possible (1 Cor 15:1-4). Jesus says “I am the door of the sheep” (John 10:7b), and again our Lord says, “I am the door. If anyone enters by me, he will be saved and will go in and out and find pasture” (John 10:9). During Jesus’ day, shepherds would gather their sheep and bring them into a pen or fenced area, and then they would lie down at the entrance of the gate or opening. This was done to ensure that no predators came in to kill the sheep. The shepherd was the gate or the door by which the sheep could come and go, but none but the sheep were allowed past the shepherd, so He acted as a gate. Jesus is the one and only way into the fold (Acts 4:12), so even the enemy has to go through Jesus to get to us. He tells us “I am the good shepherd. The good shepherd lays down his life for the sheep” (John 10:11). The hired hand runs when trouble comes (John 10:12), but not Jesus, the Good Shepherd. While the hired hand runs for his life, Jesus lays down His “life for the sheep” (John 10:15b). And Jesus is not a helpless victim of circumstances. He said, “No one takes it from me, but I lay it down of my own accord. I have authority to lay it down, and I have authority to take it up again. This charge I have received from my Father” (John 10:18). He willingly laid down His life for you; now can we lay down our lives for Him?
Jesus, our Good Shepherd, leads us into the path of righteousness (Psalm 23:3), which is His righteousness (2 Cor 5:21); He protects His sheep (Psalm 23:4); He leads us to green pastures so we might be fed His Word (Psalm 23:2a); and leads us to still or calm waters as He restores our soul (Psalm 23:2b, 3a). Isaiah the Prophet described all of us perfectly: “All we like sheep have gone astray; we have turned—every one—to his own way; and the LORD has laid on him the iniquity of us all” (Isaiah 53:6). Maybe God’s point is that we are His sheep, but we are helpless without Him. We can do nothing without Christ (John 15:5), and nothing is not a little something. Jesus knew the nature of people without a shepherd, just as a rancher knows what happens when you neglect sheep or leave them to themselves. When Jesus “saw the crowds, he had compassion for them, because they were harassed and helpless, like sheep without a shepherd” (Matt 9:36), and we are helpless too…without Jesus, our Good Shepherd. Those who trust in Christ can say as David wrote, “Surely goodness and mercy shall follow me all the days of my life, and I shall dwell in the house of the Lord forever” (Psalm 23:6).
Here is some related reading for you: Jesus the Shepherd King 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.