John 10:26-30 speaks of God's protection. Shank notes that 'following' in verse 27 is present active indicative - which could mean an ongoing action. His point seems to be that you have to follow in order to be protected and further sometimes sheep don't follow so they are unprotected and end up lost. (Shank. Life in the Son. p. 56-60)I derive a different conclusion - Christ's sheep do follow. Let's look at the passage.
In John 10:1-6 Christ says that sheep won't follow a stranger, but they follow the shepherd.
In John 10:7-8 Christ says others came before, but they were thieves and robbers and the sheep didn't hear them; basically indicating the true Israel was not led astray by false prophets.
In John 10:9-18 Christ explains that He is the door through which any man can enter and the good shepherd that lays His life down for the sheep.
In John 10:19-21 the crowd reacts - some oppose Jesus but others say "can a demon open the eyes of the blind?" This hearkens back to chapter 9's account of Jesus healing a the bind man.
John 10:22-24 says: Now it was the Feast of Dedication in Jerusalem, and it was winter. And Jesus walked in the temple, in Solomon’s porch. Then the Jews surrounded Him and said to Him, “How long do You keep us in doubt? If You are the Christ, tell us plainly.”
About 2 months had passed and the Jews ask Jesus if He was the Christ. This seems to be a trap since He they were already aware of His claim to being the Messiah. In chapter 8 Christ said before Abraham was, I AM and the Jews tried to kill him.
In John 10:25-27 Christ responds: “I told you, and you do not believe. The works that I do in My Father’s name, they bear witness of Me. 26 But you do not believe, because you are not of My sheep, as I said to you. 27 My sheep hear My voice, and I know them, and they follow Me.
The Pharisees asked Jesus "are you the Christ"? He basically says "I already told you and you still don't believe. Further, my miracles back up what I say."
The Pharisees didn't believe Christ because there were not his sheep (John 10:26). At this point Calvinists commentaries start waxing eloquent about unconditional election; but is that what Christ is saying? I don't think so, but the explanation of what it does mean undermines Shank's point.
I think it's fair to look at two different witnesses here: Christ's word and His miracles. First, Jesus told them He is Christ, and now He is backing it up through miracles. The Pharisees do not believe now, because they did not believe (and become sheep) then. If they had become sheep, they would have recognized Christ as their Sheppard and would have had a sheepish attitude which is disposed to follow. The sheep follow Christ's voice.
It’s important to understand that there are two witnesses: 1) Christ’s word and 2) the works He does in the Fathers name that bear witness to what He has said.
Jesus answered them, "I told you , and you do not believe. The works that I do in my Father’s name bear witness about me , 2but you do not believe because you are not part of my flock.
They reject #2 now, because they had rejected #1 before. But those that accepted #1 before became sheep and now follow (v 27). In this specific case, the work Christ did was healing the blind man.
Christ's sheep do follow (i.e. conversion leads to discipleship). Anyone can come through the door (Christ) and join the flock. (John 10:9) They then hear Christ's voice and follow. So when Christ says His sheep follow, He is making a simple statement about the sheep; they preserver.
In John 10:28-30, Christ says: And I give them eternal life, and they shall never perish; neither shall anyone snatch them out of My hand. My Father, who has given them to Me, is greater than all; and no one is able to snatch them out of My Father’s hand. I and My Father are one.”
All sins are some combination of temptation from without and willingness from within us. Satan's modus operandi isn't to overpower God, but rather to tempt us and lure us away from Him. If Satan were to draw us away from God (ultimately), then Satan defeated God. But that will never happen, because God's protecting hand on His sheep is too strong for Satan get us.
Thus we have 5 affirmations of eternal security: 1) Christ's sheep follow Him, 2) He gives them eternal life, 3) they shall never perish, 4) No one can take them from Christ's hand, 5)No one can take them from the Father's hand.