What does it mean that the path of the just shines more and more?

The phrase 'the path of the just shines more and more' indicates that the Christian journey is one of progressive sanctification and revelation of Christ's glory. As believers walk in faith, they begin to see more of Christ's character, grace, and love. The 'perfect day' mentioned refers to the eventual culmination of faith in the presence of God, where believers will fully know Him as they are known. This growth in understanding and appreciation for Christ enhances their ability to navigate life's challenges, all while reflecting His light to others.