So, let’s talk about this.
Since creation, God’s people have been subject to His law. When He appointed Moses to remove the descendants of Abraham from Egyptian bondage (and into the Sinai desert) He gave them a law code of their own, Mosaic Law, or the Law of Moses.
When you “rightly divide the Word of truth,” (2 Timothy 2a:15) you can clearly see through scripture that Mosaic law ended with Jesus died. At that time, all humans, everywhere, came under the law of Christ. (Galatians 6:2).
And, behold, the veil of the temple was rent in twain from the top to the bottom; and the earth did quake, and the rocks rent ~ Matthew 27:51
Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree ~ Galatians 3:13 (to read in context see Galatians 3:7-29)
And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance. 16 For where a testament is, there must also of necessity be the death of the testator. 17 For a testament is of force after men are dead: otherwise it is of no strength at all while the testator liveth. ~ Hebrews 9:15-17 (much of Hebrews addresses this)
You can read more here:
The law of Christ is comprised of information that came into effect AFTER He died. It includes some things that He and His disciples taught, the New Birth Experience in John 3 is one example. However, the specific information, or guidance, regarding salvation is contained in Acts 2. It is mentioned throughout the New Testament, but in the book of Acts, it is both described and demonstrated several times so that people can easily determine what they must do to be saved.
As you can see, the formula is consistently the same. They believed and repented, were baptized in the name of Jesus, and received the Holy Ghost (and spoke in other tongues).
The book of Acts outlines, explains, describes, and illustrates the new covenant of Jesus. As you will notice in the scripture I cited above, every single person who responded correctly then the gospel was taught, told, or preached to them was baptized by immersion in water in the name of Jesus in order to be forgiven for their sins. Some call it “coming under the blood of Christ,” but the point is you can’t come under the name or into the authority unless that name is evoked upon your immersion in water.
While we don’t have transcripts of every single person’s conversation when they were baptized in the book of Acts, we do see the pattern: that baptism by immersion in water was a prerequisite, a requirement, in order for forgiveness to be applied. Of course, faith, belief, and repentance were also required. Acts 2:38-41 explains it and the other verses noted above (as well as others) confirm it through demonstration.
The thief on the cross was not subject to the Law of Christ, the New Testament command that requires believers to be baptized by immersion in water in the name of Jesus (baptized into Christ’s death)
Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? 4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. ~ Romans 6:3-4
The thief on the cross was no more subject to the Law of Christ than Abraham, Moses, and David.
Christ had to die first and at that point He was still very much alive.
They all, including the thief, lived BEFORE the cross and therefore under different codes of law.
I will say it again, they could not be baptized into Jesus’ death because Jesus had not yet died.
Christ’s church and what is widely regarded as the “Christian religion” did not and could not occur until after Jesus died. In fact, it wasn’t until Shavuot (some call it the Day of Pentecost) that it is considered to have begun.
God is a god of order. It would have been impossible for the thief on the cross to be saved under the Law of Christ. That would have been out of order – out of God’s order.
Again, when you rightly divide the word and study scripture, you will see that the thief on the cross was saved under Mosaic law because it was impossible for him to be saved under the Law of Christ as described in the New Testament.