I was preparing a topic for my household's weekly Bible study today and thought about revisiting the crucifixion of the Lord Jesus Christ. As I have been contemplating on this topic, I cannot avoid but ask how one of the thieves hung on the cross with Christ suddenly repent and believe in Jesus. It's not true that this repenting thief did not belong to the ones who mocked Christ like some people think; as Apostle Matthew writes:

And the robbers who were crucified with him also reviled him in the same way.
Matthew 27:44 ESV

He was one of the mockers of Christ. This is not surprising for a sinner to do. However, what's actually surprising in this account was the repentance He received while being crucified on the cross for his crimes. Luke, being one the key witnesses to Jesus' crucifixion, documented this in his account.

One of the criminals who were hanged railed at him, saying, “Are you not the Christ? Save yourself and us!” But the other rebuked him, saying, “Do you not fear God, since you are under the same sentence of condemnation? And we indeed justly, for we are receiving the due reward of our deeds; but this man has done nothing wrong.” And he said, “Jesus, remember me when you come into your kingdom.” And he said to him, “Truly, I say to you, today you will be with me in paradise.”
Luke 23:39-43 ESV

If we carefully evaluate the texts, they tells us that it only took this dying malefactor a short time to have a change of heart and believe Christ as Lord. He suddenly confessed of his sinfulness, recognized that he deserved death for his sin, confirms Christ's sinlessness, professed Christ as Lord, believed in Christ's kingship and Savior-hood, and saw beyond Christ's current circumstances of suffering and shame and looked forward to Christ's victory as He comes into His kingdom. Moments ago, he was mocking Christ, and now he sees himself for the sinner that he is and begs Christ to "remember" him in Paradise. What caused Him to believe? What did He witness that triggered this change of heart? The criminals were crucified close to Christ, thus they are able to speak to one another. This grants us the conclusion that they are able to hear each other as well. Also, they are able to hear the scoffing audiences towards Christ. And we see in Luke 23:34 how Jesus uttered a prayer of forgiveness to the Father to His scoffers and murderers. He heard of Jesus praying for him. These words that Jesus uttered served as a saving sermon to him. Let's review Ezekiel's account of the Valley of Dry Bones and see how God works in man's salvation sovereignly.

The hand of the Lord was upon me, and he brought me out in the Spirit of the Lord and set me down in the middle of the valley; it was full of bones. And he led me around among them, and behold, there were very many on the surface of the valley, and behold, they were very dry. And he said to me, “Son of man, can these bones live?” And I answered, “O Lord God, you know.” Then he said to me, “Prophesy over these bones, and say to them, O dry bones, hear the word of the Lord. Thus says the Lord God to these bones: Behold, I will cause breath to enter you, and you shall live. And I will lay sinews upon you, and will cause flesh to come upon you, and cover you with skin, and put breath in you, and you shall live, and you shall know that I am the Lord.” So I prophesied as I was commanded. And as I prophesied, there was a sound, and behold, a rattling, and the bones came together, bone to its bone. And I looked, and behold, there were sinews on them, and flesh had come upon them, and skin had covered them. But there was no breath in them. Then he said to me, “Prophesy to the breath; prophesy, son of man, and say to the breath, Thus says the Lord God: Come from the four winds, O breath, and breathe on these slain, that they may live.” So I prophesied as he commanded me, and the breath came into them, and they lived and stood on their feet, an exceedingly great army. Then he said to me, “Son of man, these bones are the whole house of Israel. Behold, they say, ‘Our bones are dried up, and our hope is lost; we are indeed cut off.’ Therefore prophesy, and say to them, Thus says the Lord God: Behold, I will open your graves and raise you from your graves, O my people. And I will bring you into the land of Israel. And you shall know that I am the Lord, when I open your graves, and raise you from your graves, O my people. And I will put my Spirit within you, and you shall live, and I will place you in your own land. Then you shall know that I am the Lord; I have spoken, and I will do it, declares the Lord.”
Ezekiel 37:1-14 ESV

As the Bible says, all of mankind is dead in sin. We have all fallen short of His glory and that no one seeks after God. The valley fo dry bones shows our exact state before God, unable to come to God and obey Him. And just as how God commanded Ezekiel to prophesy over the bones in the valley, man shall hear the Word of God for man to live and recognize God and His kingdom and obey God's commandments. The Spirit causes us to love Him and seek after God's kingdom. Unless the Holy Spirit invades our hearts we shall never see God. As God has decreed, the dead bones came to life instantly. Thus, regeneration is instant and only happens once. In our short analysis of soteriology, we can conclude that it is the Spirit that caused this dying thief on the cross to repent. The event where he heard of Christ's prayer led him to recognize the Shepherd's voice. He responded to the evident eminence of Jesus' actions and he was accepted by the Savior in obedience to the Father that He will not cast out those that will come to Him.

My sheep hear my voice, and I know them, and they follow me.
John 10:27 ESV

All that the Father gives me will come to me, and whoever comes to me I will never cast out.
John 6:37 ESV

And wonderfully so, Christ promised that he shall be with Christ in Paradise after death. He was granted eternal life. The other criminal did not repent and died the way he lived: hardened and impenitent. This is the worst kind of death. Dying without the love of the Savior. The Bible warns us of this attitude towards the Gospel:

Whoever believes in the Son has eternal life; whoever does not obey the Son shall not see life, but the wrath of God remains on him.
John 3:36 ESV

I can greatly identify with the penitent thief. I am that thief on the cross. I am a sinner saved by God's grace. I was a scoffer that has been redeemed by His love for me. It's by God's Word that I came to know the truth about myself, about my sin, about God's holiness and perfection, His law, His glory, His everything. I saw myself worthy of an eternal death sentence after all the rebellion I have done against the holy God. If it was not for the Lord's grace, I would have continued on in enjoying my iniquity and have foolishly ignored the reality of God's wrath for sinners and never cared that I am going to pay for my sins in hell. I would not have seen the light if the Holy Spirit did not change my heart and opened my eyes and ears. I was about to perish, but my Lord saved me. Christ's Blood washed away my sin, my guilt and my shame and He has imputed upon me His righteousness that I may be justified before the Father. He secures my salvation. May this message transform your life the way it changed mine.