The Greek philosopher Heraclitus of Ephesus was noted for saying that “No man ever steps in the same river twice.” He recognized that the fundamental nature of the universe is that it is ever-changing and ever-moving. You might think of him as the first to understand and articulate, long before the idea of “Poisson processes” as explained in an earlier post, that life could be envisioned as multitudes of physical and life-giving processes happening near-simultaneously and probabilistically throughout time.
Jump in time up to the early 20th century when mathematician-philosopher Alfred North Whitehead (1861–1947) expanded on the work of Siméon Denis Poisson to contend that reality itself was made of events, not material substances. This concept is called process philosophy, and it has held up well in the years since then as the mysteries of the atom became better understood.
Later in the century, Charles Hartshorne (1897–2000) and John Cobb (b. 1925) added some “God language” to expand these concepts into “process theology.” There is much more to process theology than this, and I don’t do it justice here, but the idea that life is “event” rather than “stuff'” is central.
Belgian theologian Edward Schillebeeckx (1914–2009) integrated some process thought into his Catholic theology, writing that “God is new each moment,” and, “He is always surprising us.”  While Schillebeeckx was trying to give hope to humankind, suggesting that people and their societies have the volition to choose the good paths as life’s events unfold around them, he was brought to the Vatican for a dress-down at least three times, as his ideas often conflicted with traditional Catholic doctrine.
It is safe to say that “process thought” has yet to penetrate very far into the pews of most religious congregations. Indeed, its challenge to the theology of the “unchangeable God” who “knows the future,” and its clarion call to be ecologically aware and pro-active in saving the planet, is still seen as heretical in much of fundamentalist Christianity.
Still, Siméon Denis Poisson would likely today channel and expand on Galileo’s legendary dictum, spoken when he was forced by church leaders to recant his ideas of the motion of the Earth circling the Sun. “Yet it moves,” Galileo is said to have muttered. To which Poisson might well have added, “Yet it moves…probabilistically…”
- Schillebeeckx, Edward. God is New Each Moment. Continuum, 2004. p. 29.