One thing that struck me twenty years ago as I was reading what were then "old" sermons was the constant thread of sermons on the equality of women. Things like "this is going to surprise many of you, but your wives are not your property, they are your equal partners" and such. At the same time, the people hearing those sermons were completely oblivious to the message.
Part of it was a gap in metaphor (so many of the speakers had been businessmen and spoke using partnerships as their metaphor, the listeners were college students and working men).
The same with "neither black nor white" in God. There were things said about racial equality that people blatantly missed.
I would read those threads and wonder what things are we being told that we are missing but that later generations will take for granted as the truth and look at us askance?
The emerging debate about adults who have gained freedom at the expense of their children is an interesting one. I look at it and wonder how much of that will be considered true in twenty years (vs. how much will be rejected).
Theology as it evolves is fascinating, both from the threads that weave together, and those that do not.