We are commanded to be holy because God is holy, and those who belong to Him must reflect His character. Holiness is not a suggestion for believers, it is a command grounded in God’s nature and the purpose of redemption. To be holy means to be set apart from sin and devoted entirely to God.
This command was first given to Israel in the Law:
“For I am the Lord your God. You shall therefore consecrate yourselves, and you shall be holy; for I am holy.”
(Leviticus 11:44)
Peter repeats this for the church in the New Testament:
“But as He who called you is holy, you also be holy in all your conduct, because it is written, ‘Be holy, for I am holy.’”
(1 Peter 1:15–16)
Holiness is not merely external behavior. It begins in the heart and flows into every aspect of life: thoughts, words, relationships, and choices. It is the evidence of genuine faith and the fruit of the new birth.
Hebrews 12:14 puts it in absolute terms:
“Pursue peace with all people, and holiness, without which no one will see the Lord.”
Without holiness, there is no fellowship with God. The believer has been set apart from the world to live in obedience to the truth. Holiness is not perfection but separation unto God and growth in righteousness.
Paul told the Thessalonians:
“For this is the will of God, your sanctification: that you should abstain from sexual immorality… For God did not call us to uncleanness, but in holiness.”
(1 Thessalonians 4:3, 7)
Holiness is not optional or legalistic. It is the natural result of salvation. Those who have been justified by faith are being sanctified by the Spirit.
Romans 6:22 says:
“But now having been set free from sin, and having become slaves of God, you have your fruit to holiness, and the end, everlasting life.”
The Holy Spirit indwells believers to produce holiness. He convicts of sin, renews the mind, and empowers obedience.
Paul warned:
“Therefore, having these promises… let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God.”
(2 Corinthians 7:1)
Holiness is not about self-righteousness. It is about reverence for God and love for Him that rejects sin. It is the mark of the true child of God, the goal of Christian maturity, and the reflection of Christ to a watching world.