Do Christians sin?

TL;DR:

Christians do still sin, but they are not defined by a life of sin. When they do sin, they are called to confess it and receive God’s faithful forgiveness.

Christians do still sin, but they are not defined by ongoing, willful sin; rather, they are called to walk in the light and pursue holiness through the power of the Holy Spirit. The Bible teaches that all people sin, but Christians are forgiven through faith in Jesus and are being transformed to live righteously. Denying that we sin is self-deception; instead, we should be vigilant against sin and wholly surrendered to God. His Spirit enables us to put off the old man marked by carnality and sin and to grow in Christlikeness, living for what is good. When we do sin, confession brings God’s faithful forgiveness and cleansing. While sin doesn’t threaten a believer’s salvation, it can damage their fellowship with God, hinder spiritual growth, and affect others. The remedy for sin is not re-salvation, but turning to God in repentance, receiving His grace, and continuing to abide in His love.

from the old testament

While the Old Testament doesn’t mention Christians directly, it helps us answer the question "Do Christians sin?" by showing that even God’s faithful people still sinned and needed His mercy. The Old Testament affirms universal sinfulness—“Surely there is not a righteous man on earth who does good and never sins” (Ecclesiastes 7:20).
God’s people such as Moses (Numbers 20:12), David (2 Samuel 11), and Elijah (1 Kings 19:4) sinned or struggled, yet remained part of God’s covenant people.
Psalm 32:5 says that God offers forgiveness. Confession and mercy are part of God’s relationship with His people.

from the new testament

A Christian is someone who has admitted their guilt before God and accepted His free gift of salvation by believing in Jesus as their Savior. As a result, they have been made new (2 Corinthians 5:17), been indwelt by the Holy Spirit (Romans 8:9; 1 Corinthians 12:13; Ephesians 1:13–14), and seek to live a life pleasing to God (Ephesians 4:17–32; Colossians 3:1–17).
Sin is "missing the mark" of God's perfection. It is anything we do that goes against God. Romans 3:23 says that "all have sinned and fall short of the glory of God."
Christians are those who "are justified by his grace as a gift, through the redemption that is in Christ Jesus" (Romans 3:24). However, this does not mean that Christians are immune to sin.
When a person comes to faith in Christ, he is forgiven of all sins, past, present, and future. Before God, that person is deemed to be righteous. However, Christians are also still in the process of being made righteous in practice. This is referred to as sanctification. When a person becomes a Christian, he is freed from the penalty of sin. As he lives his life as a Christian, he is progressively freed from the power of sin (Romans 6:15–23).
Paul talks about putting off the "old man" and the lifestyle of the fallen world and putting on the "new man" in Christ (Ephesians 4:17–32; Colossians 3:1–17).
Romans 6:12–14 teaches that sin no longer rules over believers; instead, we are called to offer ourselves to God as instruments of righteousness, living under grace, not law.
Yes, Christians do sin. First John 1:5–10 teaches that while believers are called to walk in the light, they still struggle with sin. Denying sin is self-deception, but if we confess, God is faithful and just to forgive and cleanse us.

implications for today

Christians are positionally seen as holy when they are saved, but they are not sinless. However, we are called to live a life of willfully submitting to the Holy Spirit to allow Him to transform us into Christlikeness (2 Corinthians 3:18). Paul admits his own struggles against sin in Romans 7. In Romans 8 Paul rejoices that there is no condemnation in Christ and nothing can separate us from God's love. Christians do sin, but it is something they struggle against. Christians are not marked by a lifestyle of sin. And even though Christians sin, this does not mean that salvation is at risk or that God stops loving us. All our sin is forgiven when we come to faith in Christ. But when we sin, it can get in the way of our relationship with God. We ask God for forgiveness in order to remove the hindrance from enjoying full fellowship with Him, not in order to be saved again.

Do Christians sin? Yes. Are they marked by a lifestyle of sin? No. Does sin impact a Christian's salvation status before God? No. Can sin hinder the fruitfulness of a Christian's life and his relationship with God? Yes. Is there a remedy for sin? Yes, the remedy is through the abundant and gracious forgiveness of God who treats us as sons, disciplines us for our benefit (Hebrews 12:7–11), and desires that we abide in His love, obey His commands, and experience the fullness of His joy (John 15:9–11).

understand

Christians do sin, but they are not defined by it.
Sin does not affect a believer’s salvation, but it can hinder their relationship with God and others.
God calls all who sin to repent and find forgiveness in Him.

reflect

When you recognize sin in your life, how do you typically respond?
How have you seen God’s grace at work in helping you put off your old self and live more like Christ?
Why is it so important to recognize that you as a Christian still sin but can find forgiveness in Him?

engage

What is the difference between struggling with sin and being defined by a lifestyle of sin?
Why do you think some Christians believe that sin might threaten their salvation, and how can we respond to that with biblical truth?
How can believers practically help one another walk in the light and grow in Christlikeness without falling into judgment or legalism?