Answer: God called His children to live a holy life, (verse 7).
MORE INFORMATION AND/OR OTHER SCRIPTURE REFERENCES:
Leviticus 11:44-45: "I am the Lord your God; consecrate yourselves and be holy, because I am holy. Do not make yourselves unclean by any creature that moves about on the ground. I am the Lord Who brought you up out of Egypt to be your God; therefore be holy, because I am holy."
Matthew 5:14-16: [Jesus said,] "You are the light of the world. A city on a hill cannot be hidden. Neither do people light a lamp and put it under a bowl. Instead they put it on its stand, and it gives light to everyone in the house. In the same way, let your light shine before men, that they may see your good deeds and praise your Father in heaven."
2 Timothy 2:8-10: "So do not be ashamed to testify about our Lord, or ashamed of me His prisoner. But join with me in suffering for the Gospel, by the power of God, Who has saved us and called us to a holy life--not because of anything we have done but because of His Own purpose and grace. This grace was given us in Christ Jesus before the beginning of time, but it has now been revealed through the appearing of our Savior, Christ Jesus, Who has destroyed death and has brought life and immortality to light through the Gospel."
Hebrews 12:14: "Make every effort to live in peace with all men and to be holy; without holiness no one will see the Lord."
1 Peter 1:13-15: "Therefore, prepare your minds for action; be self-controlled; set your hope fully on the grace to be given you when Jesus Christ is revealed. As obedient children, do not conform to the evil desires you had when you lived in ignorance. 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 2:11-12: "Dear friends, I urge you, as aliens and strangers in the world, to abstain from sinful desires, which war against your soul. Live such good lives among the pagans that, though they accuse you of doing wrong, they may see your good deeds and glorify God on the day He visits us."
2 Peter 3:11-14: "Since everything will be destroyed in this way, what kind of people ought you to be? You ought to live holy and godly lives as you look forward to the day of God and speed its coming. That day will bring about the destruction of the heavens by fire, and the elements will melt in the heat. But in keeping with His promise we are looking forward to a new heaven and a new earth, the home of righteousness. So then, dear friends, since you are looking forward to this, make every effort to be found spotless, blameless and at peace with Him."