Likewise, those in the visible church, during periods of unfaithfulness, have shed to blood of faithful teachers and witnesses sent to them by God. The Roman Catholic church shed the blood of many faithful teachers sent to them, beginning about a century before Luther and continuing during the Inquisitions. Today in China, the leadership of the officially recognized Christian church aids the Chinese leadership in persecuting and killing those faithful believers and pastor who refuse to join the compromised government church. The sun shall not smite thee by day the Lord shall preserve thee from all evil. The fifth bowl strikes the seat of the beast itself who, remember, is in the religious realm on earth, supposedly representing Christianity.
Darkness is a Biblical symbol of ignorance, which can be highly self-righteous.
But yet there is no repentance, even under the awesome judging hand of God. The reason for this is always self-righteousness. Since anything which is contrary to God's Word is self-destructive, this punishment, while deliberate on heaven's part, may also be seen from earthly perspective as the natural outcome of opposition to God's Word. Scripture in many places talks about the tremendous rise of false teachers in the visible Christian Church as we draw closer to the end. This time in which self-righteous false teachers will be most effective at misleading many will not only be a time of severe testing for the faithful.