Is entire sanctification possible? Can Christians achieve sinless perfection in this life?

TL;DR:

Christians cannot achieve sinless perfection while in our mortal bodies, but we’re positionally sanctified before God once we accept Christ as Savior. Thereafter, He progressively leads us to holiness, which won’t be fully realized until Christ’s second coming.

what does the bible say?

The Bible teaches that all human beings were born with sin inherited from Adam. Genesis 3 records the first human couple’s rebellion against God, which led to death. Every human being thereafter inherited sin and death (Romans 5:12; 1 Corinthians 15:22). However, when we accept Christ as Savior, we are indwelt by the Holy Spirit and are set apart for God into a new life (2 Corinthians 5:17; 1 Thessalonians 5:23; Philippians 1:6). This doesn’t mean we become sinless, though. While we are positionally made holy through Christ, we still sin because we remain in our mortal bodies (Hebrews 10:10,14). The apostle Paul, an exemplary Christian by any measure, still struggled with sin (Romans 7:18–20). We will be fully sanctified when Christ comes again (1 Thessalonians 5:23; Colossians 3:4; 1 John 3:2). The work God began in us will one day be finished (Philippians 1:6).

from the old testament

Genesis 3 records Adam and Eve’s rebellion against God, commonly called the fall. Their sin was passed down to all of humanity (cf. Romans 5:12).
David recognized that humanity is born with sin: “Behold, I was brought forth in iniquity, and in sin did my mother conceive me” (Psalm 51:5).

from the new testament

In the Sermon on the Mount, Jesus says, "You therefore must be perfect, as your heavenly Father is perfect" (Matthew 5:48). The word translated "perfect" in Matthew 5:48 and similar verses can mean "perfect," "complete," or "mature." Because translators do not want to give the wrong idea about God (e.g., "Be mature, as your heavenly Father is mature"), they typically translate the word as "perfect." However, the idea of maturity or completeness fits the context and the overall teachings of Scripture more accurately.
For example, James 1:4 tells Christians to become "perfect and complete,” yet James 3:2 says that all believers stumble "in many ways." That implies that James 1:4 refers to being "mature and complete," not sinless.
If anyone could claim to live fully for Christ and to have reached sinless perfection, it was the apostle Paul. Yet he still struggled with sin (Romans 7:15–20).
The Bible promises a day when every believer will escape temptation and the struggle with sin. First John 3:2 says, "Beloved, we are God's children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is."
Our goal must be to grow in maturity and resist temptation (1 Corinthians 10:13). The work God began in us will one day be finished (Philippians 1:6).

implications for today

“Be good.” You probably heard that from your parents as a young kid, just before going into a store, receiving company, or going on a school trip. But even “good” kids whine for toys, start embarrassing fights with siblings in front of company, or get in trouble for not showing up to the school bus on time.

It isn’t just kids who can’t “be good;” adults have a hard time, too. Christians know that only God is truly good (Mark 10:18), but we can’t help but be frustrated that we can’t be better. We need to be reminded that when we accepted Christ as Savior, we were covered in His goodness. That doesn’t mean we’ll stop sinning. As human beings, that’s inevitable. But when we inevitably fall, we can come to God in repentance, and He will forgive us (1 John 1:9).

The sculptor and artist Michelangelo is thought to have said, “I saw the angel in the marble and carved until I set him free.” Whether he really said that or not, it’s a good way to think about how God sanctifies us—except that we aren’t angels. Yet God chisels away at us during this life to make us holier. The full masterpiece won’t be realized until the next life.

understand

Christians are positionally sanctified through faith in Christ at salvation.
Sanctification is also a progressive process after salvation.
Complete sanctification will only be realized when we see Him as He is.

reflect

Where do you see evidence of God shaping your character and growing your spiritual maturity over time?
How do you respond when you fall into sin, knowing you’ve already been made holy through Christ?
In what areas of your life do you feel tempted to strive for perfection, rather than relying on God's ongoing work in you?

engage

How can we encourage one another to pursue holiness without becoming discouraged by our ongoing struggles with sin?
What does it look like to trust God’s process of sanctification, even when progress feels slow or imperfect?
How can our understanding of future, complete sanctification affect the way we live today?