I was a toddler when my parents became JWs. I always accepted everything as truth. Changes never bothered me. I bought into the whole "new light" thing. But, I eventually had my own crisis to deal with, a marriage going bad. For me it was the lack of scriptural backing for the three acceptable reasons for a spouse to get a separation: willful non-support, extreme physical abuse and absolute spiritual endangerment. When I researched these myself (because I had (still have) such a sucky marriage) and found no Biblical backing for these, I wondered: what else has no backing? I read the Bible, some parts over and over, and found things in there that flat out contradicted what WTBTS taught. I compared translations. I used the Interlinear and Emphatic Diaglott a lot. After this, I made a conscious decision to "make the truth my own".
I asked myself: why DO we say 1914 is when Jesus was enthroned? How would I explain that in field service? Where do we get paradise earth from? Again, how do I explain this from the scriptures?
I quickly found out that not only could I not explain these things scripturally, but if I tried to do so, it would take serious leaps in bible verses taken out of context to even attempt it. I also learned about the wiggle phrases used in the literature: "in a sense", "evidently", "perhaps". And I learned how cherry-picking verses works. I learned a new term, eisegesis, which is a study of the Bible to make it fit a preconceived notions, which is exactly what WTBTS does.
After learning that I could not defend what I long believed in, my faith was extremely shaken. But, I was an uber-JW up to that point and have an uber-JW family. So, leaving, even fading, was not a realistic thing for me. I didn't know what to do. I could not talk to my wife about this. She said I was being negative about the Society and it was affecting her faith. I recall remarking: "that says something about how strong your faith is, doesn't it?" That didn't go over well. So, I continued on my "journey", as she calls it. More studying, more comparing translations.
During all this, I was made aware of how far JWs had come from actually listening to Christ. So, I focused a lot of time and energy on what he said/taught/did. I could see pretty clearly that if I wanted to continue believing in God (which I did), I had to focus on Christ. So much of what Christ said is the plain opposite of what WTBTS teaches. I found that much of what WTBTS does and teaches are things he denounced the scribes and Pharisees for doing. I realized that my faith all my life was simply misplaced in an organization that sets themselves up as "the truth", as "the way to salvation", as "God's mouthpiece". Today, I am mentally out. I am physically in... for now. For how long? I don't know. Time will tell.