Jealousy as cruel as the grave; its flames are flames of fire, a most vehement flame.
Song of Solomon 8:6
Recommended Reading
1 Corinthians 13
It seems nothing could be crueler than the grave, but according to Song of Solomon there's one thing as bad—jealousy. That's what caused Lucifer to rebel against God. It's what caused Cain to kill Abel, and Jacob's sons to sell their brother Joseph into slavery. It's why King Saul devoted his life to killing David. According to Mark 15:10, the Jewish leaders handed Jesus over to Pilate because of envy and jealousy.
That means it's no small thing to feel pangs of jealousy toward another.
If someone receives a higher grade, makes a larger salary, wins a race, achieves a victory, or experiences more prosperity in some way, are you jealous? Yes, we're all tempted to feel jealous, because the tree of envy grows from the soil of pride. But love is God's supernatural attitude that allows us to rejoice in the success of others. The Bible says, "Love suffers long and is kind; love does not envy" (1 Corinthians 13:4).
If you feel jealous toward another, that's natural. Ask God for His supernatural attitude of love. It can make all the difference.
The humble man feels no jealousy or envy. He can praise God when others are preferred and blessed before him.... He has received the spirit of Jesus, who pleased not Himself, and who sought not His own honor.
Andrew Murray