"Assuredly, I say to you, today you will be with Me in Paradise." - Luke 23:43.
Wouldn't we all love to hear these words when our race is finished, and our eyes close for the final time? Surely salvation is the goal for all men with the wisdom to consider eternity. But how do we get it? One sinner found the answer, receiving those words as a direct response to his faith.
As Jesus hung on the cross, two other criminals hung with Him. Initially, both mocked Him (Matthew 27:44; Mark 15:32). However, one of them changed his mind. "But the other, answering, rebuked him, saying, “Do you not even fear God, seeing you are under the same condemnation? And we indeed justly, for we receive the due reward of our deeds; but this Man has done nothing wrong.” Then he said to Jesus, “Lord, remember me when You come into Your kingdom.” And Jesus said to him, “Assuredly, I say to you, today you will be with Me in Paradise.”" (Luke 23:40-43).
For centuries, this has been one of the greatest examples, if not the greatest example, of salvation. He perfectly exemplifies the pattern of salvation. First, obviously, he sinned. That's why he's on the cross, and why, ultimately, any of us die. As Scripture says, "all have sinned and fall short of the glory of God" (Romans 3:23), and "...the wages of sin is death..." (Romans 6:23). He even exemplifies the natural enmity we have to God when he, along with his friend, initially mocked Jesus. As Romans 5:10 says, we were enemies with God. So initially, both thieves mocked.
But then there's a change. The thief begins to confess, and as Scripture tells us, "If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness." (1 John 1:9). But obviously, this isn't enough, one can't just accept one's own flaws. But the thief continues: "This man has done nothing wrong". And Scripture says "For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him." (2 Corinthians 5:21).
So here, the thief recognises the identity of Jesus, the sinless one. Thus, with what little time he had left, he makes a sincere request: "Lord, remember me when You come into Your kingdom." And as Scripture says, "...if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved. For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation. For the Scripture says, “Whoever believes on Him will not be put to shame.” For there is no distinction between Jew and Greek, for the same Lord over all is rich to all who call upon Him. For “whoever calls on the name of the Lord shall be saved.”" (Romans 10:9-13).
Having fulfilled all the requirements for salvation, the penitent thief immediately receives it. Thus, we see a picture on Earth of how things work in Heaven. We may not have Christ physically here, telling us we are saved, but if we follow the identical pattern; confess, repent, and believe, we will likewise be saved.
But this poses a major problem for a number of false systems. If salvation is this easy, there are a number of churches who aren't teaching the truth. These teach a number of extra stuff, much of which cannot be done while nailed to a cross guarded by well-trained Roman guards. The most obvious of these is baptism. The penitent thief shows, indisputably, that one does not need to be baptised to be saved.
In response to this, these false teachers ultimately end up objecting to the penitent thief. Denying the event itself is rare, and it's actually more common to accept extra-Biblical details. For example, the 4th century pseudepigraphal work, the Gospel of Nicodemus, ascribes him the name Dismas (or Dysmas). But even if we only go by the Biblical details, heretics raise a number of objections to the penitent thief, and his use as an example of salvation. Let's look at the top 3.
Temporary reprieve
One objection I have heard, though for obvious reasons less commonly, is that although the penitent thief obviously couldn't be baptised on the cross, maybe he was temporarily allowed back down. I don't feel much of a need to refute this claim, and I'm honestly surprised I've heard it even once. But I've heard it on at least two occasions. There are actually people out there who believe the Romans, who would deliberately whip prisoners more than 40 times as an insult to Jews, would care enough about a newly converted Christian to let him get off the cross just to be baptised.
Wishy washy God
An arguably more ridiculous objection, at least from a Christian perspective, is that God simply made an exception. God is sovereign, so He's quite within His rights to let an unbaptised person receive salvation. The problem is, this would not actually be an exception.
Throughout Scripture, faith is identified as the sole criteria for salvation. I went through a few examples when I analysed the thief's path. But it can't be denied that baptism is often mentioned alongside faith. For example, Mark 16:16 tells us "He who believes and is baptized will be saved; but he who does not believe will be condemned."
This seems to settle it. He who believes and is baptised will be saved, but he who does not believe will be condemned. But there's something to note here. Throughout Scripture, faith is often listed on its own. In Acts 16:30-31, for example, we read "And he brought them out and said, “Sirs, what must I do to be saved?” So they said, “Believe on the Lord Jesus Christ, and you will be saved, you and your household.”" Where is baptism mentioned here? It's mentioned later as a response to belief, but it's not mentioned as a requirement. What's going on, then?
According to Scripture, baptism is very important, regardless of whether or not it is required for salvation. In fact, in one often misquoted verse, Peter explains that baptism is "...(not the removal of the filth of the flesh, but the answer of a good conscience toward God), through the resurrection of Jesus Christ," (1 Peter 3:21).
If baptism is the answer of a good conscience toward God, it is unconscionable to delay it indefinitely. In fact, time and time again, whenever people converted in Scripture, their next move would be to seek out baptism. One of the biggest criticisms of the modern Church is how little resemblance we share with the early Church (as seen in Scripture) in this regard. In the first century, those who were converted were baptised as soon as water became available for it.
With this in mind, we would expect baptism to be mentioned alongside faith. It would be strange for it not to be. But while faith is so often mentioned alone, and he who merely believes is so often said to receive salvation, a lack of baptism is never mentioned alongside unbelief. He who believes and is baptised is saved, but he who does not believe is not saved. Where, in Scripture, does it say "he who believes, but is not baptised, will be condemned"?
It obviously doesn't say this anywhere, because baptism is not a requirement for salvation. We have the penitent thief as our example! "But he's an exception", they will claim. God can make exceptions, right?
First things first, is this even the kind of god we would want to follow? Look at the world today. There are nearly 200 countries, all with their various leaders. Yet, being human, these leaders are quite inconsistent. They break their own rules. Imagine if God was even remotely like them. If man is inconsistent, it leads to chaos. Why would we want to follow a god who suffers the same problem?
But regardless of what sort of God we would want to follow, we must play the hand we've been dealt. So, next question: Is it the God we have? Praise be to God, the answer is no. From beginning to end, Scripture tells us that God is not a man that He should lie or change His mind (Numbers 23:19), that there is no shadow of turning with Him (James 1:17), that He is faithful and cannot deny Himself (2 Timothy 2:13), and so on and so forth. We can be absolutely certain that God will not bend His rules for anyone. You're either saved by the rule He sets, or you're not saved. That rule is faith. It was faith before baptism was even a thing (Genesis 15:6, cf. Galatians 3:16-18; Romans 4:10-11), and it is faith now (e.g. Ephesians 2:8-10).
It's worth noting that the logic used by those who would claim otherwise is identical to the logic of those who claim faith, but live impenitent. As they rightly point out, God knows the heart. But the people who most often say "God knows my heart" are usually seeking to justify doing something they know He won't approve of. It's almost like saying "God will forgive me". If you know God will forgive you, you know you need forgiveness.
All that is to say if you start running around saying God might make exceptions because He knows the heart, you likely won't stop at baptism. It's just human nature. But it's not God's nature. Unlike us, He doesn't change. The rule He has set is fixed: We are saved by grace, through faith, not of works (which baptism is). Of course, knowing that comes with its own dangers, which Scripture warns us about, saying "...How can we who died to sin still live in it?" (Romans 6:2), and "...do not use liberty as an opportunity for the flesh..." (Galatians 5:13). But consistency seeks consistency, and inconsistency breeds inconsistency. If God can, and habitually does, make exceptions, then He can be expected to do so (and that won't always work in our favor). If, by contrast, He makes no exceptions, then we know where we stand with Him.
Under the Old Covenant
The final, and "most Biblical" (though of course, it still falls short) objection is that the penitent thief wasn't yet under the New Covenant because Jesus had yet to be raised. This logic focuses on the fact that different covenants had different rules. If the thief was still under the Old Covenant, which didn't include baptism, then obviously he didn't need to be baptised any more than Moses.
However, not only does Scripture make it abundantly clear that the penitent thief was under the New Covenant, but also, ultimately it shows that the same criteria has been active from the beginning.
First, Hebrews 9:15-17 makes it abundantly clear that the penitent thief was no longer under the Old Covenant. Speaking of it, it says "And for this reason He is the Mediator of the new covenant, by means of death, for the redemption of the transgressions under the first covenant, that those who are called may receive the promise of the eternal inheritance. For where there is a testament, there must also of necessity be the death of the testator. For a testament is in force after men are dead, since it has no power at all while the testator lives." The death of Christ, not the resurrection, rang in the New Covenant. We even see this in the Lord's Supper, as Christ says "...This cup is the new covenant in My blood, which is shed for you." (Luke 22:20, cf. Matthew 26:28). If Christ's death began the New Covenant, then the penitent thief died under the New Covenant, since Christ died first.
But the New Covenant, ultimately, doesn't annul the Old. See, according to Paul, the promise was given to Abraham a full 430 years before the law (Galatians 3:17), and he even received his righteousness by faith before he was circumcised (Romans 4:10). The criteria has always been by God's grace, received through faith, not of works.
In Galatians, Paul even goes on to apply an allegorical meaning to Abraham's two sons and their mothers. Ishmael, the son of Hagar the slave, had no inheritance with Isaac, the son of Sarah the free woman. We have to keep in mind that although we have free will, God, ultimately, is sovereign. He tells the end from the beginning, and it is He who orchestrates history.
This leads into what's called "typology", a phenomenon in which something in the Old Testament dramatically foreshadows the New. Sometimes, as with the bronze serpent, this is set up by command of God. God says "do this", the people do as commanded, and boom, there is the type. Other times, as with Ishmael, God ordains an event that needn't necessarily happen, but it was all but inevitable. Ishmael was "born of the flesh". Paul, here, gives us very explicit permission - indeed, a command - to do this with Abraham's sons.
I contend we can do this with the two thieves. It is no coincidence that Christ was crucified in the middle of two thieves, nor that one would be saved and the other condemned. It's not a case of "oh, it's cool that this thing happened and we can use it to exemplify salvation". God did this deliberately, setting two paths before us. The same two paths we see throughout Scripture. On the one hand, pride, which refuses to come to God in faith, and nothing can save us. On the other hand, faith, which God will by no means turn away.
Conclusion
These are the main (and really, the only) objections I've heard to the penitent thief being used as an example of salvation. As you can see, they really don't stack up. Whether it's showing that baptism is not some additional requirement to faith, or showing that, realistically, there is no additional requirement to faith, the penitent thief shows us that faith is all we need, and, ultimately, is all we can even have. Therefore, we should be under no delusions that we need, or could contribute anything else to our salvation. It is Christ's blood that saves us, and all we need to do to receive it is to sincerely ask Him "Lord, remember me in your Kingdom".