I was just glancing through the official website, and had an interesting thought. I know this is not original, but it struck me.
Let's begin with this quote, right off the link on their main site:
http://www.watchtower.org/e/rq/index.htm?article=article_07.htm
1. Jesus started one true Christian religion. So today there must be just one body, or group, of true worshipers of Jehovah God. ( John 4:23, 24 ; Ephesians 4:4, 5 )
Now, another link off their main site:
http://www.watchtower.org/e/jt/index.htm?article=article_01.htm
THE modern history of Jehovah's Witnesses began more than a hundred years ago. In the early 1870's, a rather inconspicuous Bible study group began in Allegheny, Pennsylvania, U.S.A., which is now a part of Pittsburgh. Charles Taze Russell was the prime mover of the group.
Are there own articles, found in 2 minutes of random browsing, not suggesting that they are not the "true religion?" Jesus started "one" religion. Russell started another religion almost 2,000 years later. How can they even attempt to reconcile this? The first quote indicates that the "true" religion must be exactly the one that Jesus started, and no other one can be true. The second quote indicates a different religion, with an origin only slighlty more than 100 years old. Without even touching doctrine, is it not obvious that their own words disqualify them as being a true religion?