"The Truth"
It's verbal trickery. Weasel words. The term is used to convince the user that the Watchtower(tm) is correct.
I think it used to be called NLP. Neuro-linguistic programming is a way of changing someone's thoughts and behaviours. A propaganda technique.
How can you be 'in' the 'truth'?
that's why I never say 'when I was in the truth.' I will say 'when I was in the cult.'