The serpent’s question in Genesis 3:1—“Did God really say?”—was the first assault on doctrine. By casting doubt on God’s Word, Satan deceived Eve and brought ruin. John Calvin noted that Satan’s method is always to “make us doubt the Word of God.” Sound doctrine is God’s answer to this ancient lie. To guard the church, we must stand firm on the authority, clarity, and sufficiency of Scripture.

Doctrine sanctifies because it is truth from God’s Word. Jesus prayed, “Sanctify them in the truth; Your word is truth” (John 17:17). Holiness comes not by human effort, but by God’s truth working in us. As Berkhof wrote, “Doctrine and life are inseparably connected.” A church that drifts from sound doctrine will drift from holiness, but one rooted in truth will be shaped into Christ’s image.