What does Psalm 15:4 mean?

The person the Lord allows to be His tabernacle guest (Psalm 15:1) understands how mankind ought to react to their Creator (Genesis 1:26–27). There are two important terms in this first phrase. The word "vile" describes a deliberately wicked, morally worthless person. "Despise" comes from a term which can also mean "to hold in contempt" or "to disdain." These are both understood through direct contrast. The opposites of those conditions are to "honor," or to esteem and respect, and those who "fear" God, in the sense of submissive reverence and obedience (Proverbs 1:7). A godly person respects those who honor God and rejects the lifestyles of those who hate Him.

This partly includes refusing to partner with evil people in evil activities. The apostle Paul commands in 2 Corinthians 6:14–16, "Do not be unequally yoked with unbelievers. For what partnership has righteousness with lawlessness? Or what fellowship has light with darkness? What accord has Christ with Belial? Or what portion does a believer share with an unbeliever? What agreement has the temple of God with idols?" The righteous person chooses to honor those who fear the Lord. He commends them, edifies them, and supports them with his fellowship and prayers.

Philippians 2:2–4 exhorts believers to honor one another by sharing the same mind and love, being unified, and putting one another's interests ahead of their own. According to this verse, the righteous person is true to his word regardless of the consequences. Even when the promise is hard, it is God-honoring to keep one's word (Matthew 5:37).