From my perspective:
Your sons are fools! My father was never one of Jehovah's Witnesses. In fact, my father was a bum. He was an alcoholic, bigamist and serial womanizer. I never even met the man. He died at 53 years old from his lifestyle. My siblings and I were raised by an unstable, religiously fanatical , dyed in the wool Jehovah's Witness mother. I will be 64 years old this year and had to make my way through life mostly on my own. No father to love and support me and give me guidance. No father to buffer me and my siblings from being raised by an unstable religious fanatic. I worked very, very hard to be a success in life but would trade it all for the love, support and guidance of a caring father. Your sons need to realize that they are very fortunate to have a father that loved and cared for them. You are worth more as a person than any religious ideology but they will have to find that out for themselves. Good luck and I hope things work out for you in the long run.