How do we know walking in the truth is vital for Christians?

Walking in the truth is crucial for Christians as it goes beyond mere knowledge of doctrine; it reflects the authenticity of one's faith. In 2 John, the apostle John expresses joy upon finding believers who not only know the truth but actively walk in it. This walking in the truth implies a life lived in obedience, one that aligns with the teachings and commandments of Christ. It demonstrates that genuine faith produces transformation in behavior and attitudes, resulting in lives that glorify God rather than seek personal glory.