Because God has made a promise to defeat evil, we must live as people of hope.

Genesis 3:15, 4:1

15 I will put enmity between you and the woman,

    and between your offspring and her offspring;

he shall bruise your head,

    and you shall bruise his heel.”

4:1: Now Adam knew Eve his wife, and she conceived and bore Cain, saying, “I have gotten a man with the help of the Lord.”