"If you are wise and understand God’s ways, prove it by living an honorable life, doing good works with the humility that comes from wisdom. But if you are bitterly jealous and there is selfish ambition in your heart, don’t cover up the truth with boasting and lying. For jealousy and selfishness are not God’s kind of wisdom. Such things are earthly, unspiritual, and demonic." James 3:13-15 (NLT)
True humility comes from wisdom, and wisdom sees the circumstances of life for what they are - the way God sees things. When we see ourselves the way God sees us - finite, in need of strength and understanding, and helpless, then we are on a path toward wisdom. It will challenge us not to think too highly of ourselves, because when people think highly of themselves, they tend to treat others lowly (less than what they are, which is unconditionally loved by God and eternally valuable). When we have a wrong view of ourselves in light of God's truth, we will always have a wrong view of others.
Unwise people don't act generously and loving toward others, but instead, see them as either an opportunity for personal gain or an obstacle to be overcome. That's where bitter jealousy will often rear its ugly head. Being angry and jealous towards someone else because their success, achievements, or possessions have trumped yours.
James says this kind of behavior is not the life Jesus created us for and died for us to experience. Notice what he says, “For jealousy and selfishness are not God’s kind of wisdom." He is saying living this way (for the believer) is NO LIFE at all. In fact, James says it's exactly the opposite of who Jesus is and how he desires us to be. Listen to the second half, "Such things are earthly, unspiritual, and demonic.” James is saying when we live this way; we are living a worldly and demonic lifestyle. "Demonic" is a strong word. I don't think any of us sets out to live like a demon, but James is saying when bitter jealousy is a part of our lives, we are acting demonic. As Jesus followers, let's choose to give up bitter jealousy, and instead, reflect Jesus Christ by loving others with a kind and unselfish love. Then you will be wise instead of worldly.