Since the world is around 6,000 years old, it still doesn't mean that the world ends around its 7,000th year . It will end, but not because of this doctrine.
This doctirne ofd the world lasting 7,000 years goes back to the early Church fathers based on their reading of Psalm 90 - For a thousand years in your sight are like a day that has just gone by, or like a watch in the night. Psalm 90:4
But what that verse is talking about is that the time & life of man is but a twinkling in the eye of God. It is NOT saying that these two measurements sof time are identical (thousand years & a day) but rather that it is a comparison between the divine and human.
Early Church father Lactnantius (An advisor to Constatine nicknmed the "Christian Cicero") stated: "Therefore let the philosophers, who enumerate thousands of ages
from the beginning of the world, know that the six thousandth year is not yet
completed, and that when this number is completed the consummation must take
place, and the condition of human affairs be remodelled for the better, the
proof of which must first be related, that the matter itself be plain. God
completed the world and this admirable work of nature in six days, as is
contained in the secrets of Holy Scripture, and consecrated the seventh day, on
which He rested from His works."
With all due respect, these ideas can be as spiritually poisonous as the "gap theory" espoused by the so-called progressive Christians. That is the idea of a million years for each day of Creation. Or even more intolerable, the idea of "theistic evolution" in which some so-called Christians believe that evolution occured over billions of yesars but God guided the process.
The answer is simple: Each day of Creation was a literal day: The earth is around 6,000 years old: and God will bring about its end when His time is ready. But of that day and that hour knoweth no man, no, not the angels which are in
heaven, neither the Son, but the Father. Mark 13:32
