If a believer stumbles in faith and even denies Christ, the LORD will bring him back.
Jesus always finds the lost sheep:
Luke 15 “3 He told them this parable. 4 “Which of you men, if you had one hundred sheep, and lost one of them, wouldn’t leave the ninety-nine in the wilderness, and go after the one that was lost, until he found it? 5 When he has found it, he carries it on his shoulders, rejoicing. 6 When he comes home, he calls together his friends and his neighbors, saying to them, ‘Rejoice with me, for I have found my sheep which was lost!’”
This is because Salvation BELONGS to the LORD and not your efforts!
He is the One who keeps us saved. He is FAITHFUL even if we are faithless. It is because we are ONE with Him and He cannot deny Himself.
2 Timothy 1 “If we are faithless, he remains faithful; for he can’t deny himself.”
1 Thessalonians 5 “23 May the God of peace himself sanctify you completely. May your whole spirit, soul, and body be preserved blameless at the coming of our Lord Jesus Christ. 24 He who calls you is faithful, who will also do it”
1 Corinthians 1 “6 even as the testimony of Christ was confirmed in you: 7 so that you come behind in no gift; waiting for the revelation of our Lord Jesus Christ; 8 who will also confirm you until the end, blameless in the day of our Lord Jesus Christ. 9 God is faithful, through whom you were called into the fellowship of his Son, Jesus Christ, our Lord.”
Once a person receives the Holy Spirit, He is SEALED permanently and nobody can break the seal.
Ephesians 1 “13 In him you also, having heard the word of the truth, the Good News of your salvation—in whom, having also believed, you were sealed with the promised Holy Spirit, 14 who is a pledge of our inheritance, to the redemption of God’s own possession, to the praise of his glory.”
Romans 8 “38 For I am persuaded that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, 39 nor height, nor depth, nor any other created thing will be able to separate us from God’s love which is in Christ Jesus our Lord.”
If a person denies Christ permanently until the end of their lives, then they were never saved in the beginning and their faith was not authentic – they didn’t have the Holy Spirit and they never truly believed in Jesus – they never knew Him.
The example of Peter – he was a true believer who denied Christ three times but was restored.
Judas was a false believer – he was never saved and he died in unbelief (Mark 14:21, John 13:11, John 17:12, Acts 1:18)
But a true believer will always be restored even if they stumble and deny Christ for a brief period.
Jesus NEVER loses His sheep:
John 10 “27 My sheep hear my voice, and I know them, and they follow me. 28 I give eternal life to them. They will never perish, and no one will snatch them out of my hand. 29 My Father who has given them to me is greater than all. No one is able to snatch them out of my Father’s hand. 30 I and the Father are one.”
Even if we wander away, He ALWAYS brings us back.