“You have a few names even in Sardis who have not defiled their garments; and they shall walk with Me in white, for they are worthy.” (Revelation 3:4) 

 We should understand this refers to regenerate saints who’ve been supernaturally washed whiter than newly-fallen snow. The Greek word translated “worthy” is axios, the root for the English word “axiom”, which means “a self-evident proof”. We see this word in New Testament Scriptures where there’s a question as to whether of not someone is saved or just faking it. “But when he saw many of the Pharisees and Sadducees coming to his baptism, he said to them, ‘Brood of vipers! Who warned you to flee from the wrath to come? Therefore bear fruits worthy of repentance’” (Matthew 3:7-8). 

 Because we’ve been redeemed by His blood, we should already be walking with Christ in white robes, so “let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience and our bodies washed with pure water” (Hebrews 10:22-23). Saints who haven’t defiled their garments understand what Solomon meant when he said “Go, eat your bread with joy, And drink your wine with a merry heart; For God has already accepted your works. Let your garments always be white, And let your head lack no oil” (Ecclesiastes 9:7-8). 

 The promise also refers to walking in white before the throne of God. Those who haven’t defiled their garments here will also walk in white in Heaven. They shall possess joys inconceivable. “Eye has not seen, nor ear heard, Nor have entered into the heart of man The things which God has prepared for those who love Him” (1 Corinthians 2:9). You’ll experience this only because of His grace. You’ll walk with Christ in white only because He supernaturally changed you, enabling you to walk "worthy", an axiomatic proof that God has saved you.