The earliest recorded ("Pre-Socratic) ancient Greek philosophers were metaphysicians who seem to have been focused on explaining change and changelessness - which was the most fundamental, and/or how the two were related and interacted*.
Since change is so obvious, why did they feel a need to impute or explain changelessness?
The answer is that if all is change then there can be no purpose, meaning, knowledge, no values - just a kind of chaos
And then one needs to explain why we spontaneously and tenaciously assume that there are such things as purpose, meaning etc.
In sum; there is explanatory need for something other-than-change if we are to have purpose, meaning, values; there would need to be a sense in which there is both directional change and eternal preservation in reality.
For Christians, in particular, there must be a way of understanding how eternal Good is possible when there is change.
When we start (as I do) with the assumption of Beings as the "units of eternal reality" we need to explain how Beings - which are alive and conscious, hence dynamic and exist in time - can both change purposively and also eternally preserve that which is Good.
If Beings must both change and retain; this implies the expansion of Beings - because beings must accumulate as well as change.
And if this is to be eternal, Beings must be expansible without limit.
Tis is easily understandable by the analogy of development - that is, the development of an organism, for example an animal, from its formation by fertilization through to mature adulthood. Such a process of development includes both directional change and is also cumulative.
For instance, in an animal there is innate or instinctive behaviour which is "given"; and there is also learning added-to (and interacting-with) the instinctive; and learning must be retained, and accumulates.
All that we need to add to the analogy is that the organism (or Being) potentially is able to continue this development without limit, and everlastingly.
That cannot happen during mortal life on this earth; but it is (I believe) what happens in Heaven, when we are resurrected eternally.
*I get this mostly from FC Copleston's History of Philosophy, reinforced by Rudolf Steiner's Riddles of Philosophy.
