God created man in his own image, in the image of God he created him; male and female he created them.

Like images of false gods and of kings in the ancient Near East, images of the true God are intended to reflect his character wherever they appear. And God’s character is utterly pure, holy and righteous. As a result, his human images are required to be utterly pure, holy and righteous, too. In 1 Peter 1:15-16, Peter wrote this:

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."

And the author of Hebrews said in 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.

Of course, fallen human beings can’t be utterly holy on our own merit. We rely entirely on Christ’s perfect holiness for our standing before God. Nevertheless, God still requires us to pursue holiness in our lives through means such as keeping his commandments.

Sadly, no matter how hard we try to obey God and keep his covenant commandments — no matter how much effort we put into being loyal to him — we’ll always fall short. As the apostle John wrote in 1 John 1:8, 10:

If we claim to be without sin, we deceive ourselves and the truth is not in us… If we claim we have not sinned, we make him out to be a liar and his word has no place in our lives.

And the answer to the Westminster Larger Catechism, Question 149, offers this summary of our inability to be perfect:

No man is able, either of himself, or by any grace received in this life, perfectly to keep the commandments of God; but doth daily break them in thought, word, and deed.

Despite the fact that no image of God, except Christ, can perfectly reflect his character in this life, we’re all obligated to pursue holiness and righteousness with our whole person. And by God’s grace, we are becoming clearer images of him through that process. That’s why in 2 Corinthians 3:18, Paul was able to write:

We, who with unveiled faces all reflect the Lord's glory, are being transformed into his likeness with ever-increasing glory.