In Matt. 1:1-17 what is the significance of 3 periods of 14 generations? How many total years is this and then what is that number divided by 42 (14×3)? Would this tell us how long a generation is? Can we determine how many generations from Adam? Can we determine an approximate number of generations from Jesus Christ’s first coming until His second coming?
We can only approximate these things, but Matthew said by dividing the generations as he did, he was identifying the time from Abraham to the Temple as one period, the Temple to the Babylonian captivity as another and Babylon to Jesus as the third (Matt. 1:17).
By combining Genesis 5 and Genesis 11:10-26 we can tell that Abraham was born 1947 years after the creation. Since we don’t know the actual year of the creation, scholars can’t agree on the year of Abraham’s birth, so we don’t know how exactly many years passed from Abraham to Jesus.
We can tell that Abraham’s was the 20th generation from Adam, and since there were 42 more from Abraham to Jesus then the total number of generations from Adam to Jesus is 62. The average length of a pre flood generation was 207 years, but by the time Jesus was born it was down to about 40 years.
Finally since we don’t know the actual time of the 2nd coming, we can’t tell how many generations will have passed since He came the first time.