That is the conclusion you must accept if you are a Jehovah's Witness as my wife tries to explain to me that even if what they are teaching today contradicts what they were previously teaching, they had the truth then and they have the truth now. The difference is, they (the witnesses and the governing body) simply BELIEVED that what they were teaching at the time was the TRUTH but when they discovered new information they adjusted their thinking. SO since they formerly believed it to be the truth, they were in the truth.
An example she gave involved people who once believed the earth was flat. Was what they believed true? It was true as far as they can tell, therefore it was true. Now that we know the earth was round, they were still believing in things that were true simply because they did not know any better. After all, encyclopedias that I consult for 'accurate information' are only true as far as the limits of human knowledge. So they are PRESENTLY true.
This kind of nonsense double talk is like nails to a chalkboard to me. The people who believed the earth was flat were not believing truth as the earth was not flat and their believing so does not make it so. If someone believed something to be true and later found evidence that contradicts that belief would be honest by simply saying, "I thought it was true, but I was wrong." That's the whole failure of the Watchtower's Governing Body when they hide behind concepts like 'new light' and 'progressive truth' to justify their doctrinal changes, they never want to admit that they are wrong.
Yet, my wife claims that the Watchtower never proclaimed that what they were teaching is TRUTH even though witnesses use phrases like, "Are you in the truth?" Instead, they are simply seeking truth unlike OTHER churches that wish to wallow in their own ignorance because they LIKE certain teachings even if they are false. I mean, nevermind the stubborness they show by holding onto 1914 CE and 607 BCE when not a single source outside the WT supports those dates due to pesky things like EVIDENCE.
In the end, when she has no more wiggle room to justify her answers she resorts to threats (be careful about how you talk about God), character assassination, and simply saying things like "one day you'll get it if only you allow yourself too." This same maneuvering I've seen in other theists (mainly Christians) when confronting atheists have caused me to call them out for being dishonest as well. It's like nails to a chalkboard for me.