Question: "How can I know that my future sins are forgiven?"
Answer: When we accept Jesus as our Savior, God forgives all our sins: past, present, and future. This statement is biblical, but we must be careful about what exactly it mean.
The statement “my future sins are forgiven” is absolutely true in this sense: Jesus died for all our sins (1 Corinthians 15:3; Hebrews 10:10; 1 John 2:2). It is biblical to say that our salvation is secure in Christ (Ephesians 1:13) and that those who are justified will also be glorified (Romans 8:30). However, we should not use the idea that “my future sins are forgiven” to imply that, once we have received Christ as Savior, we have no more need to ask for forgiveness. In other words, we must distinguish between forgiveness regarding our eternal salvation and forgiveness regarding our day-to-day fellowship with God.
Consider these passages, which point out our need for forgiveness, even after we are saved:
“If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. If we say we have not sinned, we make him a liar, and his word is not in us” (1 John 1:8–10).
“My little children, I am writing these things to you so that you may not sin. But if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous” (1 John 2:1).
In both these passages, the apostle John teaches that Christians still sin and that, when we do, God stands ready to forgive when we confess the sin to the Lord. The forgiveness is contingent upon the confession. Sin does not have to continue to separate us from fellowship with our Father. Jesus has paid for that sin, but, until it is confessed, it remains a wedge between us.
Unconfessed sin in a believer’s life is a serious matter. It affects our relationship to God (1 Peter 3:7), our relationships to others (Galatians 5:15), and at times even our physical health (1 Corinthians 11:29–30; James 5:16). We should not ignore the sins we continue to commit. We should not shrug them off by saying, “Jesus already forgave my future sins.” We must deal with them, and the Bible tells us how.
We are saved by grace through faith, and the moment we trust in Christ, we are made right with God. Our sins were forgiven (Colossians 2:13), and we start our relationship with a clean slate (Psalm 103:12; 2 Corinthians 5:21). The power of sin is broken, and we are crucified with Christ (Romans 6:1–6; Galatians 2:20). Yet, because we are still flawed humans living in a fallen world, we still give in to temptation and damage the relationship we enjoyed with God. Confession of our sin to the Lord cleans the slate once more and restores us to God.
When we are “in Christ,” our position as God’s children never changes, but our ability to enjoy a clean conscience, a pure heart, and the pleasure of our Father is hindered. Consider it this way: you are sitting by a south window on a bright sunny day. It is freezing outside, but the sun through the window is deliciously warm. Then you reach up and pull down a black shade. Instantly, the warmth ceases, and all is dark. You didn’t change position, but something has come between you and your delightful experience. Sin is like that shade. It separates us from God, and it is up to us whether we remain in that darkened condition. Confession of sin lifts the shade. God has not moved. His warmth has not cooled, but our sin blocked our ability to enjoy it.
Forgiveness from God is a priceless gift, but it came at great cost to our Lord Jesus. God does not take lightly the sins of His children and will bring discipline in order to restore our relationship with Him (Hebrews 12:4–11).
The woman caught in adultery was brought to Jesus in John 8. Rather than condemn her, Jesus offered her forgiveness: “Neither do I condemn you,” He said (John 8:11). Then He set her free, not with carte blanche to continue to sin, but with a command to cease from sinning: “Go now and leave your life of sin.” In other words, her future sins had not been automatically forgiven.