How do we know the mystery of God is true?

We know the mystery of God is true because it is consistently illustrated throughout the Scriptures. Ephesians 3:3-5 highlights that the mystery was made known to the apostles by the Spirit, demonstrating that knowledge of this divine plan is rooted in revelation rather than human understanding. The consistent testimony of Scripture, from Genesis to Revelation, culminates in the person and work of Jesus Christ, confirming that this mystery is not only true but essential to our faith. This truth assures believers of God's eternal purpose and grace.