Question: Why do we Christians have to die? If death is the penalty for sin and our sins have been forgiven, isn't that penalty gone?
Answer: That's a great question—and you are exactly correct with your premises. Death is the penalty for sin (Rom. 6:23) and Christians are, by definition, those who have had their sins forgiven...yet they still die! What gives?
Let us note the exceptions first, because not everyone has or will die a physical death. God took Enoch directly up into glory without having him experience death (Gen. 5:24; Heb. 11:5). This event prefigures Christ's future coming where those who are still alive will, in like manner, escape death (while those who have already died shall rise). So, there will be quite a few exceptions to the rule of death, but we're not talking about those exceptions today, but the topic demanded their mention. That being said, the Bible differentiates between three different deaths. First, there is the bodily death. Everyone knows about this one. That's when our biological processes cease and decomposition begins.
“And just as it is appointed for man to die once, and after that comes judgment,” (Hebrews 9:27, ESV)
Second, there is the death of our immortal souls. Our soul is that aspect of our being that does not die when the body dies. This is our real being—our unique personhood. Unfortunately, we have all already experienced the soul's death thanks to Adam.
“For as in Adam all die, so also in Christ shall all be made alive.” (1 Corinthians 15:22, ESV)
Third, the Bible speaks of the second death. This is the final death for the souls of all unregenerated persons.
“Blessed and holy is the one who shares in the first resurrection! Over such the second death has no power, but they will be priests of God and of Christ, and they will reign with him for a thousand years.”
(Revelation 20:6, ESV)
“Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire.”
(Revelation 20:14, ESV)
I'm assuming that you your question focuses on bodily death, thinking that if sin causes bodily death, then the forgiveness of sin should neutralize that same penalty. Here is where our differentiation comes in handy. Adam's sin caused all of us to be born with a triple death sentence, and if we did not take the appropriate steps for our salvation, then all three deaths would apply. For non-believers, their souls (which were born dead) would remain dead while they were still physically alive. Eventually (as with us all) their bodies would die, and their still-dead (unregenerated) souls would go to hell and later partake of the second death.
Among us who are saved, death plays out differently. We too are born with a triple death sentence, but at some point in our physical lives, we accepted Jesus Christ as our Savior. At that moment our sins were forgiven, and we became born-again...but not of the body! It was of the spirit (John 3). So, when our bodies die, our no-longer-dead (regenerated) souls still leave our bodies, but they go to heaven under the protection of Jesus Christ; since they are not in hell, they will not experience the second death.
Even though we have been forgiven our sins, our bodies must still die—because God regenerated our souls and not our bodies. Redemption is a multi-faceted process, and the redemption of our souls is only one part of it. Our bodies shall eventually be redeemed, but in the future—in the process of resurrection. But resurrection, of course, requires death. The physical death of our bodies does not pay for sins; Jesus paid it all! But our bodily deaths remain as the natural fallout of sin. In that, our deaths are naturally punitive.
There's your answer. Sin's grip has left our souls...but not our bodies. However, I can see where this answer will be less than satisfying unless we examine that first moment of sin and God's response to it. Therefore, let us travel back to the Garden of Eden to examine the details and the cause.
You are probably familiar Adam and Eve's transgression. Much of what we suffer today links to that act as its first cause. (Gen. 3:15). However, many people feel that this is unfair of God—and this is a common misunderstanding about who God is and how he works. God is not fair (as people understand fairness—that it is sort of an equity between people). He is holy, he is sovereign and he is just. It is not that he is unfair. It is just that he gets to decide on what is fair to his holiness...and sin was an affront to his holiness! Nothing can balance that out. There is no equity for God here. There will never be fairness to him because of sin. Death is, therefore, punitive; it is not about parity at all. God used his justice to sentence all of humanity to death. Yes, he is that particular about his holiness.
Fortunately for us, where justice is the rule, then mercy is an option—and we who are saved should understand this. Our souls were condemned to hell. We ran to Christ for salvation, and God applied mercy to us for Jesus' sake. But that's to do with our souls, and your question is, what about our bodies? Sorry, they still die. However, you should view bodily death as God views it; since we must live in a sin-cursed world, bodily death is much more an act of mercy than it is an act of justice, because everlasting life on today's earth with today's bodies would quickly turn into everlasting misery. I will expand on that, of course, but let's look at the trees instead of the forest for a moment.
“And out of the ground the Lord God made to spring up every tree that is pleasant to the sight and good for food. The tree of life was in the midst of the garden, and the tree of the knowledge of good and evil.”
(Genesis 2:9, ESV)
Please note that there were two named trees in the garden. One is the familiar tree of the knowledge of good and evil, and the second is the less familiar tree of life. Adam and Eve could eat of every tree except the forbidden one, so it is reasonable to assume (although not specifically indicated) that, as part of their pre-fall diet, they ate of the tree of life. But then they sinned—and God responded by banishing them from Eden. Since Adam and Eve had already proven that they could disobey God, there was a reasonable chance that they might try to get back into Eden. To prevent this, God posted and angelic guard with a flaming sword at the entrance. Let's pause and chew on this. This is an extraordinary precaution! We remember Eden to be a gentle place, so what's the problem with them slipping back in? See if you can pick out God's reason in this passage.
“Then the Lord God said, “Behold, the man has become like one of us in knowing good and evil. Now, lest he reach out his hand and take also of the tree of life and eat, and live forever—” therefore the Lord God sent him out from the garden of Eden to work the ground from which he was taken. He drove out the man, and at the east of the garden of Eden he placed the cherubim and a flaming sword that turned every way to guard the way to the tree of life.” (Genesis 3:22–24, ESV)
Did you see it? If they ate from the tree of life, they would live forever—and that's what God needed to prevent. The original methods of eternal life were now off limits. Eternal life will still be available, of course, but now the rules have changed. No one can live eternally with God without first being redeemed. Redemption is a messy business—it takes blood. And it is a longitudinal business—it takes time. Furthermore, it is a broad business. There is more to be redeemed than just the souls of humans. The entire creation had been wrecked at Eden. It, too, needs to be redeemed; just as the ground itself was cursed by God, so was biological life. That's why we must die...and under these new rules, would you want to live forever? Not I.
Yes, we're saved. The problem is that we have to hang around in these lousy bodies and wait for our deaths. Why? Because the redemption of the earth is a future event—one that we won't experience in the flesh. Until then we live in a world that has not been redeemed, and it is only appropriate that we do this with bodies suitable to corruption, bodies that have not yet been redeemed. Soul-wise we are already with God. Body-wise we are lepers living in a sewer. Death is not only our reasonable expectation, it is our glorious hope.
“For we know that the whole creation has been groaning together in the pains of childbirth until now. And not only the creation, but we ourselves, who have the firstfruits of the Spirit, groan inwardly as we wait eagerly for adoption as sons, the redemption of our bodies.” (Romans 8:22–23, ESV)
“For then there will be great tribulation, such as has not been from the beginning of the world until now, no, and never will be. And if those days had not been cut short, no human being would be saved...Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven, and the powers of the heavens will be shaken.” (Matthew 24:21–29, ESV).
I'll leave you with a handy way to remember the over-arching themes concerning birth and death. The Bible teaches this zero-sum rule of threes. If you are born once, you die twice. If you are born twice, you die once.
Those of us who are have eternal life through Jesus Christ have been born twice—physically (at birth) and spiritually (at salvation). We will die only once, and that is physically, so 2 births and 1 death equals three events. Unfortunately, there are those who have not come to Jesus for salvation. These have been born only once—at birth, so they will die twice: Once physically, and once at the second death. So, 1 birth and 2 deaths equal 3 events. They both add up...but only one makes sense.