Sound doctrine is essential for the health of the church because the church will always listen to someone, and it will always follow whoever it listens to. The only question is, will a church follow God or Satan? Will it confess the truth or lies? Will it uphold sound doctrine or false teaching?
To be specific, sound doctrine is essential for:
- The existence of the church. The church is the gathering of Christians, the gathering of people reconciled to God through the gospel. If there’s no sound doctrine, there’s no gospel. If there’s no gospel, there’s no church.
- Evangelism. If a church doesn’t have sound doctrine it cannot preach the gospel. If it doesn’t preach the gospel, no non-Christians will turn from their sin and trust in Christ.
- Discipleship. Jesus prayed, “Sanctify them by the truth. Your word is truth” (Jn. 17:17, NIV). Christians grow by learning and living in light of the truth about God—in other words, by sound doctrine.
- Unity. According to the New Testament, the only true unity is unity in the truth (1 Jn. 1:1-4; 2 Jn. 10-11).
- Worship. Jesus says that true worship is worship in Spirit and in truth (John 4:24). If a church doesn’t proclaim the truth about God then it can’t worship God “in truth.” Only by believing and teaching and proclaiming sound doctrine will the church glorify God by declaring his excellencies (1 Pet. 2:9-10) and worship him because of who he is (Ps. 29:2).