Read Genesis 3
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.Genesis 3:15 (ESV)
What is important about this passage?
This is one of the most well-know passages of the Bible. A great deal of theology centers around “the Fall”. Like the creation account, there are different opinions about this passage. Some Christians believe these events happened exactly the way they’re described in this passage. Other Christians believe this passage isn’t literally true, but that it does convey a truth — at some point humanity made a choice and sin entered into the world. There are other views (and more nuance than what is presented here), but these are the two most popular views. Either way, the story tells us that the world God created was corrupted and he would have to take action to set it right again.