What is the theme in The Norse Myths by Kevin Crossley-Holland?

Imperfect Gods is a major theme in this book. When one hears the word "god" the usual image conjured to mind is of the Christian God. This God is omnipotent, all-mighty and everlasting. He rules alone, does not resort to trickery or deceit and allows men to choose to believe in him. The gods and goddesses of the Norse pantheon are not like the Christian God.