At the start of Jesus’ earthly ministry, He proclaimed the gospel and said, “The time is fulfilled, and the kingdom of God is at hand; repent and believe the gospel!”
Since Jesus said we must repent, it must be pretty important. What is repentance? To repent means to change one’s mind. In the case of repentance before God, we change our mind about our sin, realizing that we have done evil in the sight of God, and we change our mind about God, knowing that He is holy and righteous and good.
When you repent and believe, you’re turning from something to something else. You’re turning from the direction of your sin which leads to death and eternity in hell, and you’re turning to go in the direction of Christ which leads to life and eternity with God.
But the off-ramp to turn you around from unrighteousness to God’s righteousness is grief over your sin. Second Corinthians 7:10 says, “Godly grief produces a repentance that leads to salvation, whereas worldly grief produces death.”
Joel 2:13 says, “Rend your hearts and not your garments. Return to the Lord your God, for He is gracious and merciful, slow to anger, and aboudning in steadfast love.” Psalm 7:12 says, “If a man does not repent, God will whet His sword.”
Isaiah 55:6-7 says, “Seek the Lord while He may be found; call upon Him while He is near. Let the wicked forsake his way and the unrighteous man his thoughts. Let Him return to the Lord that He may have compassion on him, and to our God, for He will abundantly pardon,” when we understand the text.