Generations
What did JESUS CHRIST mean when He said "Truly I say to you that this generation will never pass away until all these things take place" (Mat 24:34 and Mar 13:30).
Was C.S. Lewis* right when he publicly stated "And He [Jesus] was wrong. He clearly knew no more about the end of the world than anyone else. It is certainly the most embarrassing verse in the Bible."?
* see also the discernment on C. S. Lewis
We live in the last days / this present age / this (set of) generation(s).
The term 'generations of generations' is defined through the verses Deu 32:6-9 (Greek Old Testament only - the Hebrew Old Testament is very vague), Exo 3:15, Psa 72:5, Isa 58:12, Isa 60:15, and . . .
. . . is most importantly being equated with an 'eon' [G165 AIⲰN, aion = eon] in the verses Isa 34:17, Isa 51:8-9 and Joe 3:20. An 'Eon' is an 'Age' and not just a life time of 70 to 80 years (Psa 89(90):10).
This important knowledge also solves the dilemma of interpreting Mat 24:34 and Mar 13:30 "Truly I say to you that this [set of] generation[s] will never pass away until all these things take place"):
If C.S. Lewis would have used the Greek Old Testament as it was of prevalent use in JESUS' time until the rise of the Roman Church, and if he would have done a simple word study of the word behind 'generations' and discovered the respective occurrences including the term 'eon', he would have solved this riddle and not added to his transgressions.
G1074 ΓΕΝΕΑ, genea, a generation; if repeated twice or with another time word, practically indicates infinity of time. Usage: The term 'genea' primarily refers to a generation, which can denote a group of people born around the same time, encompassing the idea of a familial lineage or a period of time. In the New Testament, it is often used to describe a particular age or era, sometimes with a moral or spiritual connotation, such as a 'wicked and adulterous generation'.
From Generations to Ages
Age 1 = Adam to First Coming (Old Covenant) (see Deu 32:6-9, Heb 1:1-4, Heb 9:26)
Age 2 = First Coming to Second Coming (New Covenant) · Last Days (see Act 2:17, Heb 1:1-4, 2Tim 3:1-6, 1Pet 1:20) / This Age (see Mat 28:20, Eph 1:21, Heb 9:26) / This Generation (see Mar 13:30, 1Pet 2:9)
Age 3 = Eternity (Eternal Covenant) (see Luk 18:29-30, Eph 1:21, 1Pet 4:7)
From Eons to Ages
The noun 'eon' [G165 ΑΙⲰΝ, aion = eon] is often mistranslated with 'forever' or 'eternal', but it always means a specific period of time(s), with a beginning and an end (an age; except for eternity which is also framed as an age but will have no end).
The proof for this is found in Mat 28:20, which we would also never translate with "behold, I am with you all the days until the end of the forever". Translators can use different words for one Greek word, but it is obvious that very unfortunate choices had been made when using almost always a wrong translation as 'forever' instead of 'age', and today's translators widely copy from previous translators. The Apostolic Bible Polyglot (ABP) is a beautiful exception.
But the adjective 'eonion' [G166 ΑΙⲰΝΙΟϹ, aionos] means agelong / eternal (Mat 18:8, Mat 19:16, Mat 25:41, Mar 3:29, Mar 10:17, Mar 16:20, Luk 10:25, Joh 3:15-16, Joh 6:40 et al. His name is also ΘΕΟϹ ΑΙⲰΝΙΟϹ · Theos Aionios · Everlasting THEOS, see Gen 21:33)
The Bible also speaks of 'eternity' in other terms, e.g. through the wording 'the last enemy to be abolished is death' in 1Cor 15:22-25, 26, the wording 'at all times' in 1Th 4:17, or the wording 'eons of eons' in Rev 14:11.
The following study includes more details on this topic: