Those first century Christians certainly wanted it to be immediate. They were waiting for it.
The word most often translated as "world" in Matt. 24:14 is Strong's Gr. 3625 "oikouménē" and is "the land that is being inhabited, the land in a state of habitation, the inhabited world, that is, the Roman world (orbis terrarum), for all outside it was regarded as of no account" Source: Biblehub)
The word translated as "world" in Roman 1:8 is Strong's Gr. 2889, and is defined as an order, or the world. Thayer's has it as the earth, and hyperbole at Romans 1:8 for "far and wide, in widely separated places." Source: Biblehub
Jesus' prophesy in Matt. chapters 24-25 is of the fall of the temple in Jerusalem.
And having gone forth, Jesus departed from the temple, and his disciples came near to show him the buildings of the temple, 2 and Jesus said to them, `Do ye not see all these? verily I say to you, There may not be left here a stone upon a stone, that shall not be thrown down.'
3 And when he is sitting on the mount of the Olives, the disciples came near to him by himself, saying, `Tell us, when shall these be? and what [is] the sign of thy presence, and of the full end of the age?' (Matt. 24:1-3, YLT)
This is the subject matter for the rest of the prophesy through Matt. 25:46. The disciples asked a specific question, "when shall these be?" Jesus' answer covered all of the events that would transpire before that temple fell, which the disciples KNEW meant the end of that age! That temple was the center of their lives and they knew its destruction would change everything for them. Jesus had told the Samaritan woman at the well,
Jesus saith to her, `Woman, believe me, that there doth come an hour, when neither in this mountain, nor in Jerusalem, shall ye worship the Father; (John 4:21, YLT)
Jesus told His disciples that their generation would not pass before all the things He warned the disciples of would happen (Matt. 24:34). He told them that their house - "your house" - was left to them desolate (Matt. 23:38) "Desolate" is Strong's Gr. 2048, "eremos," a deserted, abandoned waste. (Biblehub)
Therefore, as the disciples' specifically asked when that temple would be destroyed, and as Jesus told them all the things that would happen in that generation before it fell, then the end times He prophesied was specifically for and about the fall of their temple in Jerusalem.
Paul confirmed the preaching throughout the known world - inhabited earth - of the Roman empire in Rom. 1:8, and also
which ye have heard, and which was preached to every creature which is under heaven; whereof I Paul am made a minister; (Col. 1:23, KJV)
(which "heaven" Thayer's has at Strong's Gr. 3772, 1.a as "ie. earth." In prophesy, "heaven" is often the ruling authority of the land, so in Rom. 1:8, it was the Roman empire)
and also,
'''I have fully preached the gospel of Christ. (Rom. 15:19)
As Jesus told His disciples in Matt. 24:15 that "the end" would come once the gospel had been preached throughout the inhabited lands of that old Roman empire, and as Paul told those in Romans and Colossians, and 1 Tim. 3:16 that he had preached the gospel and all the world had heard it, then the "end" that Jesus spoke of was still about the fall of that temple in Jerusalem which happened in AD 70.
The first century believers and followers of Christ, the first century converts to The Way were living in expectation of that event, and Paul told them that they knew what was coming.
And this, knowing the time, that for us, the hour already [is] to be aroused out of sleep, for now nearer [is] our salvation than when we did believe; (Rom. 13:11, YLT)
Do ye not remember that, being yet with you, these things I said to you? (2 Thess. 2:5, YLT)
They were continually being comforted and assured that "the end" Jesus spoke of was coming soon as the Apostles repeatedly told them to continue in the faith, to keep on believing, but it was not immediate. They were waiting, and wondering how long. If they had considered the time frame of a "generation" which would span an extended number of years, usually 30-40 years, then they may have known that "the end" Paul spoke of would not be an immediate event.
But, the end Jesus told them of, the end of that temple, the end of that age was the end of the old Mosaic covenant when that earthly temple fell in AD 70. It took a little time, the generation in which Christ was manifested that had to have the will and testament (the gospel) of the testator (Jesus) to be probated (preached) throughout the inhabited lands of that 4th beast kingdom of which Daniel prophesied (Dan. 2, and 7).
That 40 years exodus from the slavery of the old covenant to the freedom of the new covenant (Gal.4:25-26) was a mirror of the exodus out of Egypt and the 40 years wandering in the wilderness. That generation of Jesus' appearance on earth was a time of transition from the old law to the everlasting kingdom of Christ.
They witnessed that change. It was yet in their future when the books of the New Testament were being written and read, so the future tenses of the verbs were appropriate for their time. When we read the books now, almost 2,000 years after they were written, the verbs are not future to us. That temple fell in AD 70, and it is our history.
See further explanation from the scriptures that show what and when "the end" Jesus prophesied was about:
Testing The Spirits Part II: The End
Testing The Spirits Part III: Daniel's Lot
Frequent Mistakes Part IV: Where Was All the World
Frequent Mistakes Part VI: The End of the World ?
The Signs of Revelation Part I: The Time of His Coming
