Revelation 3:4-5

4But you [still] have a few people in Sardis who have not soiled their clothes [that is, contaminated their character and personal integrity with sin]; and they will walk with Me [dressed] in white, because they are worthy (righteous).

5He who overcomes [the world through believing that Jesus is the Son of God] will accordingly be dressed in white clothing; and I will never blot out his name from the Book of Life, and I will confess and openly acknowledge his name before My Father and before His angels [saying that he is one of Mine].