I think Chris Bounds twice has corrected me on Augustine here... hopefully I've got it right the third time ;-) Thanks, Chris!
The first individual we know to
formulate an extensive, linear philosophy of history was St. Augustine (354-430). His work called, The City of God, addressed
accusations that the gods had allowed Rome to be sacked by the Goths in AD410
because Rome had become an exclusively Christian nation.  Rather, Augustine claimed, what society was
witnessing was the ongoing conflict between two cities that existed side by
side in the world. The one was the “city
of God,” a city of heaven made up of the righteous angels as well as the “elect,”
those whom God has chosen to be saved.
While the city of God has a special connection to the “visible church” (the
people who gather together and call themselves “Christians”) you cannot see
clearly who is truly a citizen of the city of God and who is not. The visible church is like the Parable of the
Weeds in Matthew 13—the wheat and the weeds are mixed together in this world, and
we cannot know definitively which is which until the judgment.
The other city mixed together with the
“city of God” is thus the “city of humanity,” a city of earth made up of fallen
angels and the majority of condemned humanity.
Those who ultimately belong to this city are oriented around themselves
and their own pleasure, rather than God.
These two cities are in constant conflict in this age until Christ
finally returns, but the trajectory of history is toward the definitive separation
of the two at the final judgment. A
significant portion of Augustine’s work goes through biblical and secular
history to demonstrate the progress of the two cities throughout history. The implication is that we should not be
surprised when earthly cities like Rome fall, especially when they are
associated with the city of earth.
Augustine’s approach to history is
sometimes called amillennial, because he does not associate the thousand
year period in Revelation 20:4 with a literal thousand year period. For him the number is symbolic and refers to
the entire period between Christ and the final judgment. Augustine thus has a linear view of history—he
sees it headed toward a particular destination.
But he does not have a clear sense that things will develop in a certain
way in the intervening time. He does not
clearly indicate that the city of God will increasingly overcome the city of
earth or the contrary.
Two other Christian perspectives
do. Premillennialism is a
Christian perspective on history that tends to take the thousand year period of
Revelation 20 literally and believes that this millennium has not yet taken
place. Christ will reign on earth for a
thousand years after he returns to earth in the future. Generally, premillennialists tend to have a
pessimistic view of the trajectory of history.
They tend to expect the forces of evil to fight harder and harder
against God up until the time of the end. Passages like Mark 13:19 are sometimes invoked:
“in those days
there will be suffering, such as has not been from the beginning of the
creation that God created until now, no, and never will be” (NRSV).
By contrast, postmillennialism
agrees with Augustine that the millennial age has begun, but tends to see
the city of God taking over the city of earth, as it were, as time
progresses. Christ will thus return
after the millennium is over. Since it
has been over a thousand years since Christ, postmillennialists may not take
the thousand year period literally either.
The main point that distinguishes them from Augustine is thus the sense
that things will improve more and more leading up to Christ’s return.
It is perhaps
not surprising to find that Christians in different periods of time have tended
to lean in one direction or the other.
Prior to Augustine, many though not all Christians were “chiliasts,”
individuals who looked for a literal thousand year reign of Christ after his
return. From Augustine to recent times,
postmillennial and amillennial approaches tended to dominate. It is perhaps not surprising to find that the
same optimistic spirit of human progress in the days after the Renaissance and
Reformation would find a postmillennial perspective attractive.
At the same
time, we should not be surprised to find that premillennialism would rise again
in popular circles in the uncertain times of the Industrial Revolution. John Darby (1800-82) was an British
evangelist who almost singlehandedly gave birth to dispensationalism, a
Christian perspective that sees history divided up into a series of periods in
which God had a unique relationship and expectations of his people. The culmination is usually a seven year “tribulation”
leading up to Christ’s return and judgment, followed by a literal thousand year
reign of Christ on earth.
We thus cannot
say that there is a distinctive Christian perspective on the direction history
will take leading up to Christ’s return.
Each position has favorite passages in the Bible, and each position has
explanations for the favorite passages of the other positions. If we are good philosophers, we will be aware
of the forces that have influenced us in the past and are influencing us in the
present. We will be aware of our own
biases and do our best to be reflective about them.
Perhaps most importantly, we will try not to let our biases become self-fulfilling
prophecies. A self-fulfilling
prophecy is when our expectations come true not because they were inevitable,
but because our own actions, perhaps inadvertently, made them come true. If you expect things to get worse and worse,
there is a fair chance you will do things that will make them get worse. And if you expect things to get better and
better, you probably will do things that move them in that direction. Let God watch over history. Let us work for good in the world.
 By decree of the Roman emperor Theodosius I in AD380. Constantine had only made Christianity a legal
religion in AD313.