This is something that hit me just relatively recently.
The phrase "Make the truth your own" is a very famous catch phrase in JW culture. It was a pet philosophy of Daniel Sydlik and has been used and is used in talks, literature and song. Every Witness knows this trope. As ingrained as it is, I would venture to say that 99% of JWs if asked would assert that this is a scripture somewhere. But ironically, this phrase or even a thought resembling it appears nowhere in the Bible. Often when the word Truth is used, it's referring to Jesus, a "He" not a 'what' or 'where'. JW's misapplication of this phrase to themselves as a religion (i.e. "come into The Truth") contributed to this. I just think it's telling how a phrase can be repeated so often they start believing it's straight from the Bible.