Most born again Christian congregations that have been in existence for a while have well fed sheep and newbies. The newbies may be ones who have just been found by the Good Shepherd and brought in to the flock or ones that are still among the lost and the Spirit of God has been working on them drawing them to Christ nudging them to take the step of accepting Jesus as Savior. And guess what, who would the Savior Jesus be more concerned about? The well fed ones or the newbies? Surely it's the newbies. But does that mean he doesn't care for the well fed ones? Surely not. He cares for all his sheep. But he knows that the young ones require more care and he nurtures them gently and wonderfully, like only he can.
In the parable of the lost sheep, spoken of by Jesus and of which we read in Luke 15, the shepherd/owner is so very concerned about the one lost sheep that he is willing to risk leaving the 99 others in the wilderness and go after that which is lost till he finds it. That's quite perplexing. What if some of the 99 left in the wilderness wander away? What if some fall in to a pit? What if wild animals attack some of them?
The Good Shepherd knows that the well fed ones will survive a season of drought or mishap or attack by evil forces, because he himself has provided, protected and delivered them time and time again as they trusted in him while continuing in prayer, worship and meditation of his Word. He is confident that the Spirit of God to whom he has entrusted his sheep and with whom they have been sealed for eternity will guide them continually through his Word and they will survive against the odds, entering heaven at God's appointed time.
Timeless inspiration comes from the Psalmist David and both (well fed and newbie sheep) (believers) can join him by proclaiming confidently, "The Lord is my Shepherd, I shall not want".