At first, there was murder.

1 Adam made love to his wife Eve, and she became pregnant and gave birth to Cain. She said, “With the help of the Lord I have brought forth a man.” 2 Later she gave birth to his brother Abel.

Now Abel kept flocks, and Cain worked the soil. 3 In the course of time Cain brought some of the fruits of the soil as an offering to the Lord. 4 And Abel also brought an offering—fat portions from some of the firstborn of his flock. The Lord looked with favor on Abel and his offering, 5 but on Cain and his offering he did not look with favor. So Cain was very angry, and his face was downcast.

6 Then the Lord said to Cain, “Why are you angry? Why is your face downcast? 7 If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must rule over it.”

8 Now Cain said to his brother Abel, “Let’s go out to the field.” While they were in the field, Cain attacked his brother Abel and killed him.

9 Then the Lord said to Cain, “Where is your brother Abel?”

“I don’t know,” he replied. “Am I my brother’s keeper?”

10 The Lord said, “What have you done? Listen! Your brother’s blood cries out to me from the ground. 11 Now you are under a curse and driven from the ground, which opened its mouth to receive your brother’s blood from your hand. 12 When you work the ground, it will no longer yield its crops for you. You will be a restless wanderer on the earth.”

13 Cain said to the Lord, “My punishment is more than I can bear. 14 Today you are driving me from the land, and I will be hidden from your presence; I will be a restless wanderer on the earth, and whoever finds me will kill me.”

15 But the Lord said to him, “Not so; anyone who kills Cain will suffer vengeance seven times over.” Then the Lord put a mark on Cain so that no one who found him would kill him.16 So Cain went out from the Lord’s presence and lived in the land of Nod, east of Eden.

--New International Version, Genesis 4: 1 - 16.

This story was supposed to be about the first murder ever recorded in history. The cause of the incident was a simple jealousy. Cain felt jealous because The Lord preferred Abel's offering than his. The Lord told Cain that it was simply because his offering were not the best. He said, “Why are you angry? Why is your face downcast? If you do what is right, will you not be accepted?" Cain's pride was hurt because he felt superior to Abel. He was the first son, he was supposed to be the best, not the other way around. So instead of admitting his fault, Cain attacked Abel and killed him.

Jealousy is the main cause of a rotten heart. It's also the first motive for murder in this modern day. The other two are money and revenge. Its sibling, envy, is one of the seven deadly sins. Jealousy is a very powerful tool that cause to people destroy each other. People who lives in jealousy are incapable of happiness. They lost their purpose in life, because they keep worrying that they will lose. The only thing to overcome jealousy is to let it go. No matter what we do, what we earn, what we'll become, eventually everything ends. Christians believe that everything and everyone is God's gift. Therefore it's not really ours. He gives, He takes. We are just temporarily holding it for Him. Theoretically, we can't lose what's not ours.

By believing, we can never lose anything.