John the Apostle
Revelation 3:5BSB·traditional attribution

Like them, he who overcomes will be dressed in white. And I will never blot out his name from the Book of Life, but I will confess his name before My Father and His angels.

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. The preface, showing, 1. To whom this letter is directed: To the angel of the church of Sardis, an ancient city of Lydia, on the banks of the mountain Tmolus, said to have been the chief city of Asia the Less, and the first city in that part of the world that was converted by the preaching of John; and, some say...

Commenting on Revelation 3:1-6

John Gill Reformed Baptist @doctorgill

He that overcometh,.... The deadness, formality, and imperfection of this church state; gets over these things, and is among the few names in it: the same shall be clothed in white raiment; the Vulgate Latin, Syriac, Arabic, and Ethiopic versions, read, "thus shall he be clothed in white raiment"; he shall have abundance of spiritual peace and joy, great success and prosperity, both inward and...

Albert Barnes Presbyterian @notesbybarnes

Verse 5. He that overcometh. . The same shall be clothed in white raiment. Whosoever he may be that shall overcome sin and the temptations of this world, shall be admitted to this glorious reward. The promise is made not only to those in Sardis who should be victorious, but to all in every age and every land.