How do we know that preaching in power is effective?

Preaching in power involves more than mere words; it is a divine act where the Holy Spirit uses the message to convict individuals of sin, righteousness, and judgment, as elaborated in John 16:8. The effectiveness of preaching can be seen when an unbeliever encounters the truth through proclaimed Scripture, leading them to recognize their own depravity and need for Christ's righteousness. This conviction manifests as a transformative experience, in which they understand their need for grace and fall in worship before God. Paul illustrates this in 1 Thessalonians 2:13, expressing gratitude for those who receive the word as truth, not as the word of men but as God's truth that works effectively in believers.