However, all persons who have love for the truth are invited to examine this claim that Jehovah's Witnesses really do have the truth. In doing so, they should imitate what those persons in the first century did who listened to the preaching of the apostles: They received the word with the great eagerness of mind, carefully examining the Scriptures daily as to whether these things were so. Watchtower July 1st, 1979, page 25
Apparently this is an invitation that expires as soon as you are baptised. In fact if you really take them up on it before you get baptised you probably won't make yourself very welcome at the Kingdom Hall either. So not much of an invitation all round really.