Cain and Abel each brought an offering to God. In the Bible, people worshiped God by offering him their best animals or their best crops. And when they did that, they were saying, “God, you’re the most important… and every good thing comes from you… I love you.” Cain brought God an offering, but it’s clear that he didn’t really want to. After all, he didn’t bring God his best offering. And then when Abel did, Cain got mad at him. That’s another thing sin does. It makes us angry at people who do what’s right. It’s like their good choices make our bad choices stick out. God knows that sin hurts us. So God said, “Cain, you better watch out. I see what’s going on in your heart and it’s going to lead to something horrible if you don’t put a stop to it right now.” But, Cain couldn’t let go of his anger. And that happens sometimes with sin. And Cain killed his brother. But even after so much sin, God still loved his creation. He had a plan to set things right.