Eternity, Infinity, and division by zero

So I read about anti-theists saying how it's improbable that a Christian can believe in Eternity yet also believe in a 6000 year old earth (100s of millions of years is "too long").

I ponder things. I realize then, that the after-life eternity doesn't advance in the manner of the calendar of humanity. Eternity is kind of like division by zero. It's undefined. Sure, according to the calendar that we use, eternity is simply another page, another second click, etc. In after-life, eternity is probably more like the clock stops forever.

I'm tired right now. If I figure out more, I might post.