Why is sound doctrine essential for a Christian’s discipleship and growth?

Sound doctrine is essential for a Christian’s discipleship and growth because what we believe determines how we live.

1. A Christian will only grow in loving and worshiping God as he understands more and more about God’s holy character, and infinite power, and sovereign grace (1 Pet. 1:16; Heb. 13:5-6; Tit. 2:11-14). We worship God because of who he is (Ps. 29:2). Therefore, the more we know about God, the more we will be inspired to worship him.
2. A Christian will grow in holiness as he grows in understanding God’s holiness, the sinfulness of sin, the propitiatory work of Christ for all who believe, and the promise of Holy Spirit-given obedience (Isa. 6:3; Rom. 1:18; Rom. 3:21-26; 1 Cor. 6:19-20; 2 Cor. 3).
3. A Christian will grow in humility as he grows in understanding just how exalted God is above all creatures, and what a great offense sin is against God, and just how humble Christ became in order to save him from his sin (Isa. 59:2, 55:8-9; Phil. 2:5-11).
4. A Christian will grow in love for others as he grows in understanding how God has loved him in Christ (1 Jn. 4:10-11).
5. A Christian will grow in sharing the gospel with others as he grows in his own understanding of the gospel.
6. A Christian will only be able to instruct other Christians as he grows in his own knowledge of the Scriptures.

The entire Christian life depends on sound doctrine: we can’t worship God or grow in holiness or serve others or share the gospel without it.