I am going through the book of Mark on your web site. You say in chapter 3 that anyone who is a believer can never blaspheme the Holy Spirit. I understand that but, What if that person decides in his heart that he no longer is a believer and turns away and becomes a agnostic or atheist. Is he ever able to turn back to Christ?
This question comes up frequently, but the answer bears repeating. According to Ephesians 1:13-14 and 2 Cor. 1:21-22 when we became believers, the Lord sealed the Holy Spirit in our hearts as a deposit guaranteeing our inheritance, which is eternal life. At that point the Lord accepted responsibility for keeping us saved. In John 10:27-30 Jesus said that no one can take us out of His or His Father’s hands. Notice He didn’t say, “No one but you.” He said, “No one.”
2 Cor. 1:21-22 also tells us God has set His mark of ownership on us. Here’s how that works. In 1 Cor. 6:19-20 Paul said we are not our own, but have been bought with a price. According to 1 Peter 1 :18-19 that price was the precious blood of Christ. Put it all together and it means when we asked the Lord to save us from our sins, He literally purchased us with the blood of His son, and marked us to show that we now belong to Him. No one else can purchase us, and we can’t walk away.
So, we’re like the sheep who belong to their owner, but don’t realize that, and think they have the freedom to wander off. When they do the shepherd goes after them and brings them back, because that’s his job.
Most Christians don’t understand that they actually belong to God. Sometimes they rebel and may even say they’ve renounced their relationship with the Lord. But the Holy Spirit knows what’s really in their heart, so if that happens the Lord will go after them like a shepherd goes after a lost sheep and will bring them back. He does this because He has promised never to lose anyone the Father has given Him. (John 6:38-40). If you can’t think of anything else to thank Him for today, thank Him for that.