How do we know that God's Word is effectual?

Paul asserts in 1 Thessalonians 2:13 that the Word of God effectually works in those who believe. This means that the Word is not mere information but a dynamic force that brings about change and life. It is God's method for delivering His grace and meriting transformation. This effectual working is evident in the lives of believers: they experience the power of the Gospel, leading to true spiritual rebirth, life, and a new identity. It is by this power that the believer sees their sin, recognizes their need for a Savior, and ultimately trusts in Christ alone.