Perhaps better than any other chapter in the Bible, Leviticus 19 explains what it meant for Israel to live as a holy nation. Through Moses, God spoke to the people, saying, “Be holy because I, the LORD your God, am holy” (Leviticus 19:2). Both the Old and the New Testament stress the importance of cultivating personal holiness in the life of every believer: “But just as he who called you is holy, so be holy in all you do; for it is written: ‘Be holy, because I am holy’” (1 Peter 1:15–16).
In Hebrew, the words translated “holy” and “holiness” have to do with being “set apart,” “separate,” “different,” or “dedicated.” The absolute moral purity of God’s character sets Him apart, making Him different from every other living creature. Yet He calls His people to be holy as He is holy. Humans generally think of holiness as obeying God’s law. But, for God, holiness is not a mere action or a set of behaviors. Holiness is His essence. God is morally and ethically perfect by nature. So how can we set ourselves apart to reflect God’s holiness in the way we live?
The Bible reveals that God’s holiness of character is a model for believers’ lives and our shared communion with others. Both passages (Leviticus 19:2 and 1 Peter 1:16) and their surrounding verses stress that those who wish to replicate God’s holiness must reflect His holy nature in their relationships with other people and their sincere love for fellow believers.
In Leviticus 19:1–37, God applies the Ten Commandments to various areas of life, spelling out in great detail for the Israelites how to be holy as He is holy. They were to honor their parents, keep the Sabbath, not practice idolatry, worship and offer sacrifices properly according to God’s instructions, provide for the poor, not steal, cheat, seek revenge, and not follow pagan customs and rituals. The commands continue, covering every aspect of spiritual, moral, family, work, and community life. Included is the charge to “love your neighbor as yourself. I am the LORD” (Leviticus 19:18).
Peter also lays out how we can live in the light of God’s command to be holy as He is holy. First, he says to discipline our minds: “So prepare your minds for action and exercise self-control. Put all your hope in the gracious salvation that will come to you when Jesus Christ is revealed to the world” (1 Peter 1:13, NLT). We are to exercise self-control and stay alert both mentally and spiritually. This mental discipline requires a concentrated focus on trusting in the Lord to get us to our final destination, where we will experience the fullness of God’s grace in Jesus Christ.
Paul expresses it like this: “Not that I have already reached the goal or am already perfect, but I make every effort to take hold of it because I also have been taken hold of by Christ Jesus. Brothers and sisters, I do not consider myself to have taken hold of it. But one thing I do: Forgetting what is behind and reaching forward to what is ahead, I pursue as my goal the prize promised by God’s heavenly call in Christ Jesus” (Philippians 3:12–14, CSB). If we focus only on the short-term—our current situation—we run the risk of straying off course. But if we live with total trust that Jesus Christ will return to accomplish all that He started in us (Philippians 1:6), it will make a significant difference in how we live.
“You must live as God’s obedient children,” says Peter, “Don’t slip back into your old ways of living to satisfy your own desires” (1 Peter 1:14, NLT). When we “do not conform to the evil desires” (NIV) we had before we came to know Christ, we live in response to God’s holiness, adopting His behavior as our pattern.
This change of behavior begins on the inside with our attitude and mind-set. When our inner thought life, our purpose, and our character are changed into the image of Christ, our outward selves and outworking behavior will alter naturally. This process is the Holy Spirit’s work of sanctification: “And we all, who with unveiled faces contemplate the Lord’s glory, are being transformed into his image with ever-increasing glory, which comes from the Lord, who is the Spirit” (2 Corinthians 3:18).
As part of his teaching on cultivating holiness, Peter instructs believers to “live out your time as foreigners here in reverent fear” (1 Peter 1:17). Living as strangers here on earth hammers home the idea that our earthly lives with all their challenges and struggles are only temporary. Even in our pain, we can live with hope as citizens of a future heavenly reality. Reverent fear refers to humble, respectful awe of God, which motivates us to live obedient, holy lives.
Finally, Peter makes the point that living in the light of God’s holiness means demonstrating “sincere love to each other as brothers and sisters. Love each other deeply with all your heart” (1 Peter 1:22, NLT).
Believers ought to be notably different from non-believers and their old selves because of their relationship with God through Jesus Christ. His holy presence in our lives produces in us a loving obedience to God’s Word, which ultimately forms God’s character in us. If we are set apart for God’s use, separated from our old, common way of living, we are following God’s command to “be holy for I am holy.”