Brian D McLaren's 2021 book Faith After Doubt sets a framework for understanding faith development in four stages: Simplicity, Complexity, Perplexity, and Harmony.
Spirituality is evolving from dualistic to pragmatic, then critical, and ultimately into non-dual thinking,
McLaren gives people permission to doubt beliefs made obsolete with new science, scholarship, and an expanding worldview. The book may be particularly helpful for evangelical Christians who have moved from certainty into the deconstruction of traditional beliefs and are "lost in reconstruction," looking for a system that brings integration and harmony.
What I find most interesting is the implications for how the Christian religion, particularly in the United States, is likely to evolve in the future. For many years church membership has been in a steady decline with a rise in "nones," particularly among younger generations. Few churches actually aim to help people navigate through their doubts.
Faith communities that are quite progressive in their methodology may be rigidly conservative and regressive in their theology. On the other hand faith communities that are progressive in their theology may be rigidly institutional in their methodology - "Big on committees. Big on vestments and keeping the liturgy just so. A little low on action and energy. Really nice people... of my grandparent's generation." The result is that "nones" and those with doubts have fewer places to go to resolve these concerns and just give up on being part of a congregation.
Observers have noted that politics has replaced religion in terms of the fervor of beliefs.
People are still looking for purpose and belonging, but instead of meeting in building with stained glass windows, people are looking for meaning through podcasts and TED Talks.
They are getting together and finding belonging by starting reading groups in living rooms and pub theology groups in bars and restaurants. Instead of attending church "52 times a year," they meet less frequently "for 52 hours" in festivals, retreats, excursions into the wilderness, and conferences.
Churches are facing an "open-source revolution."
"Doubt prepares the way for a new kind of faith after and with doubt, a humbled and harmonious faith, a faith that expresses itself in love..... "We need churches that are big on action and big on love, but small on beliefs and bureaucracy." ~ Brian McLaren
This all reminds me of Living The Questions that I participated in several years. ago. Their curriculum "explores the biblical foundations, theological grounding, and
spiritual practices at the heart of Progressive Christianity."