I'm not a Jehovah's Witness, nor have I ever been one. (Neither have I played one on TV.) But I have relatives who joined back in the late 60s, and we've heard precious little from them since.
I've read many JW publications, talked to their missionaries and am at a loss. They seem convinced that the Watchtower Society is God's kingdom on Earth and that it represents His interests on the Earth. That's fine by me, but how in the world does any Witness know, or claim to know, that God agrees with this? As far as I know, no one claims prophetic guidance in the organization. There are no angelic ministrations, no visions from the Almighty, no rushing of winds, no fiery pillars, no tongues of fire or speaking in tongues. Since God anciently manifested Himself by such means, making known His will to men, doesn't it stand to reason that Jehovah's "earthly organization" would have some communication from God to confirm its validity? In the section on mind control, I saw many references to their publications' claims, but it's like the old preacher who says, "Oh, God, if thou didst send me, do thou nothing O, Lord, and I will know assuredly that thou hast truly sent me! But if thou didst not send me, O God, send me an angel at once to correct my misunderstanding, lest I speak falsely in thy name!" And hearing nothing, the preacher went his way rejoicing.
Alexander Campbell claimed a restoration of Christianity could be gained through a tenacious study and strict adherance to the holy scriptures. "Where the Bible speaks, we speak," he said. "Where the Bible is silent, we are silent!"
This is a somewhat more rational response, but what do the Witnesses say when asked concerning their claims to be Jehovah's organization on Earth? Or am I missing something? Ellen G. White claimed to have heard from God. So did Joseph Smith. And Muhammad. But I can find nothing that would give the most ardent Witness the confidence to state that his church and organization was of God.