First of all we note that the return of Christ is sudden and unexpected. These things had already been taught to the Thessalonians.
This kind of prophecy is unique to the Word of God. There is no ancient human literature ever said anything like this. That the history of mankind would go on and would be a history that could be viewed as various clear seasons or periods of time. That is how we study history very often today. We think of the Dark Ages, the Middle Ages. We think of this period and that period. We think of the Victorian era. We think we can analyse history in socio-economic terms, or geographical terms, or in spiritual terms – the prevailing attitude of people to God. We think of the modern age and the post-modern age, and of course the last great apostasy, the era of unbelief which we seem to be into now.