How do we know that transformation in Christ is real?

Transformation in Christ can be identified through the impact it has on a believer's life. As Paul states in Ephesians 4, those who have truly learned of Christ are called to put off their old nature and be renewed in the spirit of their minds. This renewal manifests as a genuine desire for spiritual growth and obedience to God's will. Those who are transformed by Christ exhibit fruit in their lives that aligns with the truth of the Gospel, demonstrating the Holy Spirit's work within.

Essentially, a transformed life will not resemble the old ways associated with the 'Gentiles'—the ungodly. Instead, believers will show evidence of having been taught by Christ through their actions, thoughts, and desires. This progressive sanctification is indicative of the ongoing work of the Spirit in a believer's life, affirming their identity in Christ and their commitment to live according to the truth.