How do they convince "believers" that they are "ordained" from God to teach the rank and file?
They just say they are and the R&F believes it! Of course, a lot of religious do the same; somehow the clergy has a special relationship with God that the laity doesn’t enjoy. However, JW’s will say that they don’t have such a church hierarchy with class distinctions, but their religious structure speaks otherwise. Please consider: if it looks like a duck, walks like a duck, quacks like a duck, swims like a duck, it’s probably a duck!
What scriptural evidence do they give to prove that JW's are supposed to go through an organization for biblical interpretation, and pledge their loyalty to it, to boot?
As mentioned by "
greven ," they interpret Matthew 24:45-51 as applying to a so-called "anointed class." There are a number of problems with this interpretation, however. They also claim to have been punished by God for 3 ½ years, starting in 1914, for holding fast to the teachings of false religion (so-called, "Christendom"). Somehow, however, God determined they would repent, because he appointed them "the faithful slave" "class" in 1919, even though they had not make any changes up to that time and for many years to follow! Have your parents explain this! If they don’t agree, then have them explain what doctrines were changed before 1919 that allowed "God’s people" to be released from "Babylon the Great." I don’t know of any!
For example, the "cross" was used up to 1933 (circa… I’m pulling this from memory… if you want I can be more specific I can look this up; I do recall an old-time JW mentioning this change—they lived through it). Many other beliefs were held beyond the 1919 date. This included the teaching that the Egyptian Pyramid at Gaza, somehow figured-into the Biblical end-time calculations of the Bible. This was later rejected years after 1919—but according to an old-timer friend of mine was still be taught in the congregations well into the 1930’s! Remarkably, the "powers-to-be" in Brooklyn-Bethel (Watchtower) currently say that (somehow) God foresaw that his people would make changes after 1919, so credited them with having made major doctrinal changes prior to 1919, even though they had not made any, not a single one (go figure)!
Anyway, which is it: were they "naughty" or "nice" in 1914 (they claim to be viewed by God as the "Faithful Slave" starting in 1914). If they were "faithful " and "discrete" then why did God have to cast them into figurative "Babylon the Great," in order to be punished, because they were very wicked, as described in the book of Revelation (as they claim to fulfill)? And how could God thereafter view them as the "faithful and discrete slave," when they hadn’t made any changes in their doctrines up to 1919 and well beyond? Once again (I’ll assume your parents won’t initially agree), ask your parents which doctrines were changed, then look them up in the "Proclaimer’s" book (JW’s recent history book) to see when they actually were changed!
The misapplication of Matthew 24:24-51 is very sad, because a closer examination shows that it was really meant to help disciples of Christ Jesus not set a date for his return! This was the real reason the illustration was given. If you look carefully, there is only one "slave" mentioned in the prophecy. He could turn out "faithful and discrete" or "evil." Hence the "slave" is really individual "Christians" from the time of Christ until now.
What is the difference between the two courses of the "slave?" Please read the illustration and you’ll find that somehow the "evil" slave figures-out that his "master" is "delaying" and subsequently "beats" his fellow "slaves." Now how would he know this? Evidently, he somehow determines the time of his Lord’s return, whereas the "faithful and discrete" slave does not do so. He waited patiently, knowing the "master" could return at any time. Because the master doesn’t return when the "evil" slave determines, he "beats" his fellow slaves.
Previously, Jesus said "prove yourselves ready, because at an hour that you do not think to be it, the Son of man is coming." (Matt. 24:44) This verse occurs just before the "faithful and Ddiscrete / evil slave" illustration. Really then, the illustration was to help Christ’s disciples be always ready, but prevent building false expectations/speculations of his return! Please realize this runs counter to JW beliefs! JW’s believe that, somehow, one can calculate when the Lord is going to return and that, somehow, this was in 1914!
Anyway, ask your parents how many "slaves" are mentioned in this illustration! Most JW’s will answer two. However, even Watchtower acknowledges that there is only one "slave" in the illustration (see Watchtower’s "God’s Kingdom of a Thousand Years", 1973, pages 358-360). This is a real eye-opener to most JW’s from my experience! I'm sure your parents will be surprised too. Then the next logical question is, if there's only one "slave," then how does the Watchtower come up with two "slave classes?"
What is it that is being taught to JW's to make them believe the WTBS is "God's visible organization"?
Once again, the R&F is basically taught to accept it without question. JW meetings are basically set up to teach people how to be "tape recorders;" they learn how to "record" and "playback" teachings that are not really based on the Bible, but are "messages-from-God" from the "mother," Watchtower-organization!
Hope this helps! Best Wishes!