Joel Engardio's documentary Knocking features two Jehovah's Witness families, the Knights and the Kemplers. Joseph Kempler gives the most compelling reason for serving Jehovah I've ever heard.
As a teenager, Kempler was shuttled though six Nazi concentration camps and survived them all. He was interred as a Jew and freed as a Jew. While confined, though, he observed Jehovah's Witnesses. After the war he became one.
"It's difficult to speak to Jews," he says. "They say I became a traitor. Six million Jews died and I joined the other side.
"I was among those survivors who felt that God was really responsible and guilty. He was the one who permitted the Holocaust. So we didn't fail him, we didn't do anything wrong. He failed us. And this is a very common belief.
"God is being maligned and misunderstood and in many different ways looked down upon as being uncaring or dead or whatever, and there are all kinds of distortions as to what God is and who he is. To be able to speak up in his defense....what a powerful turnaround from somebody where I was to become a defender of God...what a wonderful privilege this is."
It is a privilege. Mr. Kempler recognized that and grabbed hold of it, even in the aftermath of suffering that turned millions away from God, millions who could not fathom how God could possibly permit such a monstrous thing. Yet accurate Bible knowledge conveys the reason for both suffering and persecution, how God will ultimately work matters out, and how his worshippers should respond in the meantime. Armed with such knowledge, Jehovah's Witnesses survived what was likely the greatest evil in history, with faith and dignity intact,
What is remarkable about the account is how so many people today go the other way in the face of far less provocation. Mr. Kempler saw, in the holocaust aftermath, an opportunity to defend God. But people today, even some of our own people, sever all ties with God for reasons no more substantial than personal inconvenience, having somehow lost all ability to conceive of any life beyond the here and now. Such is the power of a materialistic age where self is the focus.
God being where he is and we being where we are, and we in distinctly imperfect form, one might imagine him keeping us at arm's length. Instead, we're told that we can serve him shoulder to shoulder, as if he considers us equals!
For then I shall give to peoples the change to a pure language, in order for them all to call upon the name of Jehovah, in order to serve him shoulder to shoulder. Zeph 3:9
and that it's possible to be his friend:
and the scripture was fulfilled which says: “Abraham put faith in Jehovah, and it was counted to him as righteousness,” and he came to be called “Jehovah’s friend." Jas 2:23
Inherent in defending God is speaking about him. You cannot read the gospels (literally "good news," Mark is the easiest; it moves the quickest) or Acts (the early history of Christianity's spread - "acts" of the apostles - things they did) without sensing that the ideas expressed were not to remain private but were to be offered to others. So speak Jehovah's Witnesses do.
The Bible consistently likens spiritual things to water. Water is healthy when it moves and stagnant when it does not. If Christians take it in through reading, meditation & congregation meetings, then their public ministry serves to keep in flowing. People have lots of views today, and, as a way of proclaiming "truce," a popular notion is that religion is too "private" to discuss, at least, to discuss with strangers. Plainly, JWs don't feel that way. To be sure, to keep "pushing" something upon someone who's made it clear they don't want it is ill-mannered. (though that doesn't necessarily preclude a later call. People change.) But the other extreme, labeling faith as too personal to even discuss, is not in keeping with the nature of Christianity.
In spite of their public visiting, Jehovah's Witnesses are a "live and let live" religion. Their "weapons" are ideas only. When you tell them "no," they go away. Sure, they try to be persuasive, but it's still only words. They don't afterward attempt to legislate their beliefs into law, so as to force people to live their way, much less resort to violence.
To be a defender of God is a rare privilege indeed.
More on Knocking here and here
2021 Update: Footage on Joseph Kempler from the U.S Shoah Foundation here