2Co 4:18 because we do not look for things that can be seen but for things that cannot be seen. For things that can be seen are temporary, but things that cannot be seen are eternal.
Jud 1:25 to the only God, our Savior, through Yahushua the Messiah, our Lord, be glory, majesty, power, and authority before all time and for all eternity! Amen.
From H5956; properly concealed, that is, the vanishing point; generally time out of mind (past or future), that is, (practically) eternity; frequentative adverbially (especially with prepositional prefix) always: - always (-s), ancient (time), any more, continuance, eternal, (for, [n-]) ever (-lasting, -more, of old), lasting, long (time), (of) old (time), perpetual, at any time, (beginning of the) world (+ without end). Compare H5331, H5703.
From G165; perpetual (also used of past time, or past and future as well): - eternal, for ever, everlasting, world (began).
What is eternity? Simply put it is a different dimension. In eternity there is no measurement of time.
Please let that sink in. We her on earth in this life are conditioned to measure things in a linear way using time as a way to track everything in our existence. We see in the Hebrew word (properly concealed, perpetual, before and after) it is important to realize how different the dimension where the Kingdom of Heaven is from what we are for the most part currently experiencing.