Scripture says He will appear the second time (Hebrews 9:28)...
This is true.
...and never a third time.
This is your adding to Scripture. You will not find a chapter and verse for this limitation to ONLY a second coming .
Because that isn't taught in scripture. Do you care about interpreting scripture accurately?
Scripture does speak of the ranked order of resurrections in 1 Cor. 15:23. Christ was the First-fruits, and afterward, those who were His at His coming (the second coming of Hebrews 9:28). Many other Scriptures state the timing for this second coming and a resurrection that the New Testament writers testified was
"about to be" in that first-century generation, just as Christ had predicted in Matt. 16:27-28 - while some of those people back then were still alive to see this return.
But the second coming was not supposed to be the period on the end of the sentence of history. It was a semi-colon.
Why wouldn't it be on one occasion only? Do you think of God as a God who does not do things efficiently? Scripture teaches that He will judge all people at the same time when Jesus comes at the end of the age (Matthew 13:36-43, Matthew 13:47-50, Matthew 25:31-46).
The Apostle Paul wrote that the "ends of the ages" had come upon them back then in 1 Cor. 10:11. Hebrews 1:2 called those first-century days "the last days", 1 John 2:18 wrote that "it
is the last hour", and 1 Peter 4:7 said that "the end of all things is
at hand" in his own days. God was about to sweep the dead, decaying remnants of the Old Covenant worship system into the trash and burn them to ashes in the AD 66-70 period.
You are correct that ALL the dead were to be judged in those texts that you brought up. But what you fail to grasp is that this was
ALL the dead who had died up until AD 70 which were going to be judged, with rewards given to all according to their works. After that AD 70 judgment of ALL the dead, anyone who would die following the AD 70 return of Christ would
also be required to stand before the judgment seat of Christ to be judged according to the things they had done in the body. This necessitates a
third coming and a final resurrection and judgment for us in the future.
God set up the pattern for this three-stage resurrection process back under Mosaic law, with the three required harvest festivals of Passover, Pentecost, and the Feast of Tabernacles predicting the exact day on which God would stage three bodily resurrection events. Two of those group resurrection events have already occurred at Passover in AD 33 and AD 70's Pentecost day, leaving only the symbolism of the Feast of Tabernacles to be fulfilled in a final group resurrection to complete the pattern set up long ago.
I believe they were asking for the sign that would indicate that the temple buildings were about to be destroyed since the last thing they were told before asking their questions was that the temple buildings would be destroyed. So, it makes sense that they would only have asked about that. I believe that they probably assumed that His coming with His angels when He would judge or reward everyone according to their works, as He had previously told them about (Matt 16:27, Luke 12:35-48, etc.) would occur at the same time that the temple buildings were destroyed and Jesus would have known that they assumed that and would want to correct that misunderstanding.
Naaah, Jesus wasn't correcting anything. He was
confirming the signs of His first-century coming in the disciples' own generation. This was exactly what He meant by giving the disciples that list of signs to look for in Luke 21:3-8-35. At the end of giving that list, Christ warned them in verse 36, "Watch ye therefore, and pray always, that ye may be accounted worthy to escape all these things that are
about to come to pass, and to stand before the Son of man."