The Kingdom Promised
Luke 23.39-43:
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.” He said, “Jesus, remember me when you come into your kingdom.” He said to him, “Truly, I say to you, today you will be with me in paradise.”
While we can’t really be sure, it is fully possible that the thief being crucified next to Jesus was able to grasp the idea that Jesus’ life was not ending after His crucifixion but that He instead would be transcending our physical world into that eternity from which He came in order to provide that same eternal promise for all of humanity. Regardless, the thief would become one of the first to enter paradise by grace through faith in Jesus Christ. (Ephesians 2.8-9)
Jesus promised the thief that he would be in paradise that day with Him because he accepted and believed in the Son of God. Clearly, this is an example that a person is saved by grace alone through faith, rather than by works, as those who persecuted and condemned Jesus would have had the people believe.