I have been reading through the Old Testament Book of Amos. The main theme is God's judgement (both present and forthcoming) on Israel for the injustice endemic to the society. This is very challenging today.
As an aside (which is hopefully not just an intellectual distraction) two particular verses got my attention (Amos 5:7 and 6:12):
7 O you who turn justice to wormwood
and cast down righteousness to the earth!
But you have turned justice into poison
and the fruit of righteousness into wormwood
I found these verses interesting because of the issues raised in an old post about "wormwood" in the Book of Revelation. The wormwood [just like locusts, fire, a plumbline, ...] may be an allusion to Amos.
This supports the view that Revelation is not about predicting specific events in a chronological sequence leading to the return of Jesus. Rather, it a call to Christians to perserve in living out their faith in a world full of injustice and suffering.