Jehovah's Witnesses pride themselves on being like-minded and speaking in agreement. There is no disagreement within the organization. To them this a strong indicator that they have the truth. After all they are one of very few religions where all members believe exactly the same way. This is confirmation that they have 'the truth' and all other religions have false doctrines.
Some Jehovah's Witnesses have told us that in most religions it's hard to find ten people who think exactly the same. Yet in their religion seven million people worldwide agree on everything the Watchtower says. To them this is absolute proof that no other religion has interpreted the Bible better than they have. To Jehovah's Witnesses unity of beliefs is all the evidence they need that they are God's chosen ones.
Critics however say that it's not normal in any society for millions of people to agree on absolutely everything. They say to reason for agreement is mind control.
The Jehovah's Witnesses pride themselves in being independent thinkers who just happen to agree with everything they read in God's word as interpreted by Watchtower publications. They know it's the truth, the moment they hear it. Happy Witnesses always feel they are free and able to believe in anything they want as long as they always choose 'the truth' as explained by 'God's organization'. Of course the only source of truth they know of is the faithful and discreet slave. To them this is God's channel of communication.
If one wants to continue being a Jehovah's Witness, rebellion against the 'slave' is not allowed. Disagreement can easily lead to disfellowshipping. According to the Watchtower 'rebellion against the slave is rebellion against Jehovah'. Watchtower June 1, 1956 page 346. Also see the Feb 15, 2009 Watchtower.
It is unknown how many JW's live with nagging doubts about some or all Watchtower doctrines. These cannot be expressed to anyone, - even close family members. There's always a chance that even a loved one could report negative comments about the organization to the Elders.
Leaving the organization can be painful and liberating at the same time. Unfortunately for most JW's, the price of leaving is greater than what they're are willing to pay. For this reason it is believed that Jehovah's Witnesses secretly believe whatever they want to believe, yet outwardly they fiercely defend all doctrines and speak in agreement.
Jehovah's Witnesses agree on everything at least in public. It is risky to say anything to the contrary, even with family and your closest friends. Everyone is required to report disagreement to the elders. Thus most Jehovah's Witnesses secretly live with many doubts.
Not only are they isolated and separate from people outside of their organization, but they are also isolated as individuals within the organization. They cannot express their doubts to anyone. Doing so can easily lead to disfellowshipping and being shunned by everyone that matters in their life. The need to speak in agreement is more important than anything else.