This is a very good question to ask an active JW as I did some 2 or 3 years ago, having just read to him the scripture about there being no felowship between false religion (idolatry etc) and christianity, according to Paul.
The guy I asked did not answer, he could see the trap I had laid, how could it be the "Truth" when some falsehood (they would perhaps use the word error, or even the milder "wrong understanding") was part of it ?
So, as has been said, it never was, and still is not the "Truth", in any way.