How do we know that being godly is necessary for Christians?

Godliness is emphasized throughout the New Testament as a reflection of a true believer's heart. In 2 Peter 1:3-4, Peter notes that by God's divine power, believers are given all things that pertain to life and godliness. This means that godliness is not merely a duty, but a result of God's gift to believers — a supernatural impartation that aligns them with the character of Christ. For believers, godliness demonstrates their faith in the gospel and reveals the nature of their salvation. It shows that they are set apart by God for His purposes, guiding their conduct and character in a way that honors Him.