It is too often assumed that the gospel needs to be heard by unbelievers, but not by believers.  The gospel exists to convert sinners; once converted, we can move on to other things.

This is a fallacy, as Cameron Smart shows.  I summarise eight reasons why seasoned Christians need to hear the gospel on a regular basis.

1. To evoke praise and thanksgiving. We should never tire of praising God for what he has done for us in Jesus Christ his Son.  See Romans 11:33–36; Revelation 5.
2. To remind us of who we are in Christ. We can so easily become distracted and forgetful.  Focusing on the gospel focuses us on Christ (Col. 3:1–4; 1 Cor. 15:1–11), and our identity in him.
3. To feed us. Constant meditation on gospel truths ‘roots our faith, makes us fruitful, feeds us, waters us, grows us, and keeps us firm through trials’.  See Psalm 1; John 6:22–59; Jude 20–21.
4. To keep us from sin. When we keep the gospel constantly in mind we grow in our love for our Father, and desire to please him in our lives.  ‘Knowing that there is no good thing we can do that would make God love us more in Christ actually frees us to love and obey him rather than to take advantage of His grace (see all of Romans 6).’
5. To motivate us to do good works. The good news of resurrection of Jesus Christ frees us to give, give, and give again for others.  See Tit. 2:11–14; Eph. 2:1–10.
6. To protect us from despair.  ‘Nothing can separate us from the love of Christ, which was shown to us through the gospel of the Cross (Rom. 8:31–39).’
7. To encourage others around us.  When we rejoice daily in the gospel, we are in a better frame of mind to encourage others.When we’re reminded of the gospel, we are more prone to share a word of encouragement with others throughout the day.  This builds them up in their ministry and in their daily lives.  See 2 Tim. 2:1–7.
8. To beat down our pride.  ‘A sober reflection on our sin and what God has done for us in the gospel destroys our pride and cultivates a spirit of humility before the Lord and others (John 3:16, 5:24; Tit. 3:1–7).’