To us the past is unchangeable -- water under the bridge. The future, however, is as uncertain as the forecast of rain and impossible for us to fully predict or know. The only point where the “changeable” meets “certainty” for us is in the present. But, is that also true of our infinite Creator? What if the past, present and future remains both certain and changeable to God? As some have put it, “God is in the eternal now.”
