How was the thief on the cross saved without obeying the Gospel and being Born Again? There was no Gospel to obey because, Jesus had not died yet, nor had he been buried or resurrected. Therefore, Jesus’s requirements to obey the Gospel and be Born Again were not in effect, until after Calvary. II Thessalonians 1: 8, John 3: 5-8, John 7: 38-39
What then was required in the scriptures for salvation before Calvary?
The Bible states in Luke 16: 16 – The Law and the Prophets (Old Testament) were until John. Then came John the Baptist preaching in the wilderness of Judaea, and saying, Repent ye: for the kingdom of heaven is at hand (Matthew 3: 1-2). Also, Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand (Matthew 4: 17).
Therefore, in obedience to the scriptural requirements before Calvary, the thief on the cross repented (Luke 23: 39-43). This is how the thief could be saved without obeying the Gospel and being Born Again.
However, after Calvary, Jesus gave the Gospel (requirements for salvation) to His Apostles. Jesus told them, that the whole reason why He had to die; was so that repentance and remission of sins should be preached in His Name, among all nations, beginning at Jerusalem. Then they were instructed to wait in Jerusalem until they received the promise of the Father (Holy Ghost) Luke 24:44-53. See also Acts 1:1-8, Matthew 28:19-20, and Mark 16:15-16.
Consequently, what did the Apostles teach after Calvary? …. repent and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost (Acts 2: 38).
God’s Blueprint for the New Birth is encapsulated in Acts 2: 38 and exhibited in Acts chapters 8, 9, 10 & 19. This is how every Christian is Born Again; by obeying the Gospel. God’s Plan of Redemption (the Gospel) is the common salvation and faith once delivered by the apostles and spoken of by Jude. How to be Born Again by obeying the Gospel is clearly revealed in the Bible.
However, rightly dividing the word of truth is key to understanding the Bible and finding God’s Plan of Redemption. Believe what you read in the Word of God. Then you too, can become a recipient of the greatest experience on earth. According to Hebrews chapter eleven, faith has always been obedience to God’s Plan, and “The just shall live by faith”. (Hab 2: 4, Rom 1: 17, Gal 3: 11, Heb 10: 38)