We look not at the things which are seen, but at the things which are not seen; for the things which are seen are temporal, but the things which are not seen are eternal. (2 Corinthians 4.18 LSB)

Sometimes in life we run into something that feels like it is taking "forever" to get done. It is a "figure of speech" - a hyperbole.

The truth is, we do not understand "forever" or "eternity" quite fully. As of today, most of us are not 100 years old yet. Maybe in the future, some of us get to live way past 100 years old. The science looks promising.

And still, a hundred or few hundreds of years is just a blip in the scale of eternity. So we would never truly understand eternity.

But by faith:

We know that if the earthly tent which is our house is torn down, we have a building from God, a house not made with hands, eternal in the heavens. (2 Corinthians 5.1 LSB)

And

In My Father’s house are many dwelling places; if it were not so, I would have told you; for I go to prepare a place for you. (John 14.2 LSB)