"For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord" (Romans 6:23). Sin is that which is opposed to God. It is rebellion against God's rule and results in separation from Him. Because God is life (He is the only eternally existent Being and therefore contains existence within Himself; see John 8:58; 14:16; and Exodus 3:14), the result of sin is lack of life – or death. Without Jesus, sin results in eternal death. However, sin has consequences beyond an eternity in hell.
The consequences of sin - What are they?
Those who have been saved in Christ are given eternal life (1 John 5:11-12), and this life begins now. The Christian is not merely given a ticket to heaven but is ushered into fullness of life (John 10:10). While on earth, we experience the true abundance of our lives in Christ only in part; the Christian life is a foretaste of what is to come (1 Corinthians 13:12). But, it is still a taste. There is still the experience of true life. Sin disrupts this. Even for a believer, sin results in symptoms of spiritual death.
Though believers in Christ have been forgiven of their sins (2 Corinthians 5:21), they are still undergoing a process of sanctification. This means that we are forgiven and justified before God, yet still in the process of being made completely new in Christ. Though we are declared righteous, we do not always act righteously. Therefore, our sin still has an effect. Much like a parent still loves a disobedient child, God still loves us when we sin. If we have been saved, our sin does not threaten the security of our salvation. In fact, our salvation does not hinge on our righteousness; it is founded on the righteousness of Jesus. We were dead in our sins and totally unable to save ourselves; it was God's love for us that resulted in salvation (Romans 5:8; Colossians 2:13; Ephesians 2:1-5). As believers we do not experience separation from God when we sin; however, we do experience a break in our relationship with Him. There is tension in our communion with Him. As a result, we may experience confusion, loneliness, guilt, purposelessness, or the like. This is what spiritual death feels like. For believers, this is not a permanent state. But it is a consequence of unconfessed sin.
Sin also carries certain natural consequences with it. God's rule is designed to be for our good. He created us and knows us intimately. He knows what is good for us and what is not. He does not create rules or give commands simply so that we will obey Him. God does not need to engage in a power struggle for the sake of His ego. He knows He is in control and His rule is loving. This means that our rebellion against God is really rebellion against what is best for us. A parent knows that too much sugar will result in health problems for his child, and that a lack of sleep will result in crankiness. The parent does not limit candy or impose bed time just to control the child, but for the child's benefit. When the child disobeys, he or she suffers the natural consequences of engaging in destructive behavior.
Sometimes sin also leads to the consequences imposed on us by society. Certain sins are illegal. When we are caught committing these sins, even if we repent and are restored to the experience of full life in God, we may suffer legal consequences.
For believers, sin does not result in ultimate death. Our salvation is secure in Christ. We need not be "re-saved" when we sin. However, our sin does have consequences. When we sin we hurt both ourselves and God. We need to confess our sins, repent of our behaviors, and seek restoration with God. He promises to forgive (1 John 1:9; James 5:15-16).
What is sin?
The sin nature - What is it?
Does my private, personal sin affect others?
Are all sins equal?
How can I know what is a sin and what isn't?
Truth about Sin