JWs teach that 'accurate knowledge' is the definition of truth. They add to this by saying that the 'conduct' of average church goers also identifies them as not being in the 'truth.' And, they define their 'organization' as being the Truth, because they are a clean people who are doing right works, and teaching accurately. They define what they consider correct doctrine, no trinity, no hell, no soul, no heaven for most people, no birthday cake, no voting, no politics, no war, no blood, no association outside the religion, no sassing the Elders, no sports, no school dances, and no smoking.
Ex-JWs sometimes impose variations of this definition upon other religions ... especially Catholicism ... where one can enjoy a piece of B-day cake, have a drink, and enjoy a fine cigar ... and those funny dressed Bishops, and the Catholic Church does this or that or whatever ... and don't forget the Inquisition ... and there you have it ... Catholics do not have the truth either.
Some Christians define Jesus as the Truth (according to Jesus own words - good) and thus reject all Churches. They in effect become their own Pope of a Church of One Person. What does Jesus being the truth mean about truth? How is Jesus the Truth?
Catholics define truth as Jesus - he is the way, the truth and the life ... and what that means to a Catholic is that all Jesus did and said that he taught orally, and passed on to the Apostles, who in turn passed on the same oral teaching and tradition to the disciples. Jesus gave the Apostles authority (not to rule or lord it over) but to pass on the sacraments and his teachings. Catholics make mistakes, sin, and do both good and some do harm ... Catholics do not claim to be more than human sinners, and the Church is where most fine healing.
Aside from Roman Catholicism and Orthodoxy, no other churches can trace their tradition back to the early Church (The Apostles) in this way. Most non-Catholic Churches simply refer to the Bible as their sole and central foundation. We see how the Catholic and Orthodox faiths have remain essentially unchanged and united ... whereas the 'Bible" oriented Churches and Individuals, have all gone off in all sorts of directions ... and we see the extremes found in groups like the JWs.
Catholics do accept that elements of the Christian faith is found in the various non-Catholic churches ... and that the salvation of individual Christians in various Churches, including the JWs, and Mormons, Adventists, and others, is dependant upon God and the individual's faith in Christ ... notwithstanding, the liturgy, sacramental validity, and teaching of non-Catholic churches is not complete ... not necessarily false, just incomplete.
What say you? What is truth to you ... how do you define truth ... does it even matter to you?