Human life is holy, holier even than the Scrolls of the Torah. Its holiness is not man’s achievement; it is a gift of God rather than something attained through merit. Man must therefore be treated with the honor due to a likeness representing the King of Kings.
Not that the Bible was unaware of man's frailty and wickedness. The divine in man is not by virtue of what he does but by virtue of what he is. With supreme frankness the failures and shortcomings of kings and prophets, of men such as Moses or David, are recorded. And yet Jewish tradition insisted that not only man’s soul but also his body are symbolic of God. This is why even the body of a criminal condemned to death must be treated with reverence, according to the Book of Deuteronomy (2 1:23). He who sheds the blood of a human being, “it is accounted to him as though be diminished [or destroyed] the divine image.”—Abraham Joshua Heschel in Moral Grandeur and Spiritual Audacity: Essays, 84–85
He keeps going, but that's enough for today. This section reminds me of the C.S. Lewis essay/sermon entitled "The Weight of Glory," which also gave it's title to the book, Weight of Glory (the other essays are well-worth your time, too).
We are all image-bearers of God. Whatever happened in Gen 3 didn't erase that image. It might have defaced it, making us "cracked eikons," as Scot McKnight puts it, but it didn't erase that image. Remember that as you face what you think are your enemies. Remember that when you are tempted to hurl insults at others. They, too, are images of their (and your) creator!