All OT prophecy has not been fulfilled. Consider the following verse from
Zephaniah:
Zephaniah 3:8 ¶Therefore wait ye upon me, saith the LORD, until the day
that I rise up to the prey: for my determination is to gather the nations,
that I may assemble the kingdoms, to pour upon them mine indignation, even
all my fierce anger: for all the earth shall be devoured with the fire of
my jealousy.
Compare the burning of the earth with II Thes 1:7-8
2 Thessalonians 1:7 And to you who are troubled rest with us, when the
Lord Jesus shall be revealed from heaven with his mighty angels,
8 In flaming fire taking vengeance on them that know not God, and that
obey not the gospel of our Lord Jesus Christ:
Notice also Peter’s promise that the earth would be burned:
2 Peter 3:7 But the heavens and the earth, which are now, by the same
word are kept in store, reserved unto fire against the day of judgment and
perdition of ungodly men.
Peter goes on to say that he was still looking for a new heavens and a new earth
(II Pet 3:12) at the time that he wrote around AD 60, for the old one had
not yet been consumed by fire as the prophets require. It is apparent that
Zephaniah, Paul and Peter are all talking about the same day, and both
Paul and Peter said the day was still in the future even in the days of the
apostles. Zephaniah has not yet been fulfilled.
