Actually, the last time the phrase is used in the WTS publications is in the 1988 Revelation Climax book. It is also used in one of the songs in the current songbook. Most JWs are not familiar with the term. Most think of the idea of brighter light in connection with Proverbs 4:18. The phrase can be found in some Bible translations at 2 Peter 1:12 and this is how it looks in the NWT:
2 Peter 1:12 NWT12 For this reason I shall be disposed always to remind
YOU of these things, although YOU know [them] and are firmly set in the truth that is present [in YOU ].
Revelation Climax Chapter 8 Revelation-Its Happy Climax!
8 An even stronger reason for publishing this book is the need to keep up-to-date with present truth . Jehovah is continually shedding greater light on the meaning of his Word, and we can expect that our understanding of Revelation, along with other prophecies, will be sharpened as we draw closer to the great tribulation.
Here is the scripture in the King James Version and Young's Literal Translation.
King James Version 2 Peter 1
12 Wherefore I will not be negligent to put you always in remembrance of these things, though ye know them, and be established in the present truth .
Young's Literal Translation 2 Peter 1
12 Wherefore, I will not be careless always to remind you concerning these things, though, having known them, and having been established in the present truth,