Here's something I wrote once in answer to your question:
If asked, “What is the truth?” Jehovah’s Witnesses will answer most likely like this: “The truth is that which is firm, trustworthy, stable, faithful, and established as fact. Jehovah God is truth, in that His judicial decisions, law, commandments, and word are truth. He cannot lie according to Titus 1:2.” They won't say it, but they really think anything printed by Watchtower is "truth." Seeking an answer elsewhere, Webster defines “truth” as: (1) being true; specif., a) sincerity; honesty b) conformity with fact c) reality; actual existence d) correctness; accuracy (2) that which is true (3) an established fact. Wikipedia (online encyclopedia) mentions that “ there is no single definition of truth about which the majority
of philosophers agree.” In John chapter 18, Jesus told Pontius Pilate that he came into the world to “ bear witness to the truth,” but when Pilate asked, “What is truth?” there was no answer from Jesus. There are various opinions on how to define and identify truth. Even with Webster telling us that truth is “that which is true,” I could make a statement and say that it is a true statement, but that just leads to questions such as these; What is a true statement? Is it different from a statement made truthfully? Such highly abstract discussions will get us nowhere. Some feel that truth is subjective and personal, that one man’s truth comes from his inner feelings and thinking, his viewpoint. Many add that truth is relative, only defined by its comparison to something else. This would be similar to the abstract question, “What is beauty?” In subjective truth, different persons would have different truths. Outside of philosophy, truth is not generally thought of in subjective terms. Truth is determined by existing realities, based on facts independent of the mind. Most people think that truth is objective. Some go so far as to say that only absolute truth matters. "Absolute truth" is defined as inflexible reality: fixed, invariable, unalterable facts. Absolute truth requires an absolute standard. This is the truth of which the Watchtower organization refers. Even here, we can run into trouble. If I make the objective statement that “Earth is the third planet out from the sun,” another person could ask, “ Whose definition of ‘planet’ are you using?” “Is it possible that there are other undiscovered planets between the earth and sun?” “When you say ‘out from the sun,’ do you mean in distance or a straight line?” With religious doctrine, it is no different. Whose translation are we using, and which ancient Greek or Hebrew meaning are we applying? The Watchtower claims that our perspective on truth should come from the absolute authority of the creator of all things. They teach that the creator determines what is right and what is wrong, and that the absolute truth we seek is knowledge of His will for His creation. This is “the truth” that, unlike beauty, does not lie in the eye of the beholder. It’s just a shame that we need humans to interpret what that absolute truth is, and to tell us what they think God’s will is for us. ..... Since the Watchtower teaches absolute truth, I simply have to demonstrate that it is false or not absolute. This is surprisingly easy to do. ....
