The founding motives of a movement are baked into it for its entire lifespan. A movement cannot evolve beyond its original purpose.
Christianity began as an apocalyptic movement. The world as it was known was about to end and be radically transformed by the coming of the Son of Man. The Faith does not make sense without that expectation. The end is always near, or the Church settles into stagnant dogma and tradition. The New Testament’s ethical teachings are less a handbook for ordinary moral living than instructions for how to conduct oneself in the last days.
For two thousand years, Christian predictions of the end have been wrong, yet the predictions keep coming. Christianity thrives on apocalypticism; without it, the movement loses its purpose.
