What is the context of Jesus words here when He uses the phrase "this generation?" Some have interpreted this generation to mean the generation that was alive when He came the first time. Jesus was explaining things to do with the end times and His reference to "this generation" should be in that context.
This generation refers to the generation living during the end time. The signs of Matthew 24-25 will be experienced within one generation, the generation living when Christ returns.(1)
The events of Matthew 24 are much too universal and cataclysmic to represent the dreadful but geographically limited devastation of Jerusalem (in 70 A.D.). That did not involve "famines and earthquakes" (Matt.24:7), believers being "hated by all nations" (v.9), false Christs (Messiahs) and false prophets (vv.5,11), the preaching of the gospel to the whole world (v.14), or the abomination of desolation (v.15). Nor were the sun darkened, the moon extinguished, or the stars dislodged from their places (v.29).(1)
Jesus was speaking as some of the Old Testament prophets often spoke, as if they were standing directly before future generations (see, e.g., Isa. 33:17-24; 66:10-14; Zech. 9:9).(1)
Matthew 24:34 is an explanation of the parable of the fig tree. The idea is that, just as the budding of fig leaves means it is not long until summer, so the generation alive when the signs occur will not have long to wait for Christ's appearance. Those who witness the birth pains will witness the birth.(1)