For you were straying like sheep, but have now returned to the Shepherd and Overseer of your souls. (1 Peter 2:25 ESV)
All throughout scripture, people are referred to as sheep. God is referred to as the Good Shepherd. When sheep follow the voice of the Shepherd, they are protected from predators and led to places of sustenance and safety.
Sometimes sheep go astray. This is dangerous because sheep are meant to follow. So when one sheep goes astray, it usually means that others are right behind them going in the direction of danger willingly. Instead of listening to the voice of the shepherd, they listen to another member of the flock leading them off the path.
We, as humans, can be led down this same path. The tendency to follow the majority has led many people to be misled and deceived. It is imperative to listen to the voice of the Good Shepherd so that we are not deceived.
How do we do this? We stay in His Word and fellowship with the flock that is intent on following the Shepherd.
Some Christians try to go to heaven alone, in solitude. But believers are not compared to bears or lions or other animals that wander alone. Those who belong to Christ are sheep in this respect, that they love to get together. Sheep go in flocks, and so do God's people.
- Charles Spurgeon