I am currently rereading the three Berdyaev books I own - Slavery and Freedom, The Meaning of the Creative Act, and Freedom and the Spirit - and I have discovered that much of Berdyaev's thought aligns with Dr. Bruce Charlton's concept of Romantic Christianity.
As far as I know, Bruce has drawn much of his external inspiration for and understanding of Romantic Christianity from the Gospel of John, Owen Barfield, Rudolf Steiner, and William Arkle, among others. I have read the Gospel of John and William Arkle's A Geography of Consciousness, but I know practically nothing about Barfield and Steiner.
Nevertheless, based on what I have gleaned from Bruce's blog over the past year or two, I can with some confidence state that Berdyaev foresaw the need for the same sort of Romantic or Mystic Christianity thinkers like Steiner and Barfield addressed in their own works. The terminology likely differs, but from what I have been able to gather, the overarching themes overlap, as demonstrated by the passage below excerpted from Berdyaev's Freedom and Spirit:
We are entering upon a period of new spirituality, which will be the counterpart of the present materialism of our world. There will also be a new form of mysticism corresponding to this new period in Christian history. It will henceforth be impossible to oppose the conception of a higher life by pointing to the sinfulness of human nature which must be overcome.
There is no longer any room in the world for a merely external form of Christianity based upon custom. It is precisely the mystical and spiritual life which leads to victory over sin. The world is entering upon a new period of catastrophe and crisis when we are being forced to take sides and in which a higher and more intense kind of spiritual life will be demanded from Christians.
The sort of Christianity which is purely outward in character and never rises above the level of mediocrity is today on decline; while that which possesses eternal significance is growing more intense and stronger.
I consider this sort of overlap fascinating. All I need to now is get my hands on some Owen Barfield or Rudolf Steiner so I can experience the overlapping themes firsthand.