Reading this book, how did I react? Honestly, with envy. The Underground Church members' persecution forces them to stay in their Lord's protecting arms all the time with all possible distractions, worldly interests, taken away. Their devotion to Him is enormous.
The copyright says this book was published in 1967 or 1969. I wonder what the state of Christianity in Russia and former Soviet states is now, since it probably doesn't have to stay underground.