Eternity is related to state of being timesless, whereas Infinity is related to anything which cannot be counted or measured. Eternity relates to “time” and infinity relates to “many dimensions”.
Eternity specifically refers to the possible infinity of time, either going forward into the future or backwards into the past or sideways even (if time has more than one dimension). Eternity is a concept that is temporal in nature and applies to things that are timeless.
“If we consider eternity, into that time never entered; eternity is not an everlasting flux of time, but time is as a short parenthesis in a long period; and eternity had been the same as it is, though time had never been.”
– John Donne
Eternity is forever. But what would this mean, especially because eternal life in one form or another is the ultimate promise of almost every Religion?
Is there instant perfection, to be maintained forever? Progress to be made? What would we do forever? Wouldn’t we get bored? Would the flow of time seem the same? How to fathom a literal eternity?
How to imagine the experience of eternal life? Would we sense ourselves? How would we feel? Whom would we know? What would we do? What would any possible deity do? Living forever seems so absurd, yet eternal life is the promise of almost every religion. But if we cannot even imagine what eternal life will be, how can we have hope in its reality?
“Time is the moving image of Eternity.”
All beings – stones, beetles and philosophers – are in some (almost impossible to specify) sense in time, but only one has the idea of time.
Man is the being for whom time, uniquely, is explicit: he times time, translating the apparent movement of the sun into hours on the clock and months on the calendar. He alone has placed inverted commas around it and called it ‘time’.
Even infidels must acknowledge this mysterious background whence the notion of eternity – whether it is unending time, timelessness, or a container that transcends and encloses time – has emerged. The concept of eternity raises questions about what kinds of beings we are, where we fit into the order of things; more specifically whether we are perhaps so fundamentally different from other creatures that a different fate may await us when our hearts stop beating and our supply of tomorrows gives out. These may seem dangerously heretical thoughts for an Agnostic, but the very existence of the idea of eternity keeps the door of its possibility ajar.