For you were going astray like sheep; but are now returned to the Shepherd and Overseer{"Overseer" is from the Greek episkopon, which can mean overseer, curator, guardian, or superintendent.} of your souls.
But on the word sheep there is no particular stress; he indeed compares us to sheep, but the emphasis is on what the Prophet adds, when he says that every one had turned to his own way. The meaning then is, that we are all going astray from the way of salvation, and proceeding in the way of ruin, until Christ brings us back from this wandering. 