For the writers of New Testament Scripture there were two ages (αἰών aiōn), this present evil age, and the coming eternal age.
When Christ taught His disciples to pray (Matthew 6 version), "Our father which art in heaven, hallowed be thy name. Thy kingdom come. Thy will be done even in earth as it is in heaven..." your eschatology/two-age paradigm would seem to require Him to be speaking of the Father's kingdom as "the coming eternal age" and His will on earth must mean enduring suffering and persecution on earth ("this present evil age"). The post-mil perspective sees a kingdom coming on earth as it is in heaven, to bring in the fulness of the elect through the spread of the Gospel, before a final apostacy, ingathering of the sheep, and final judgment. Part of the reason for apostacy is because many will profess to be Christians because they see the earthly benefits - have we not already seen many glimpses of this in history (the Roman Empire being the first)? Otherwise, how do you interpret Christ's declaration of what the parable of the tares means in
Matthew 13.41-43? "The Son of man shall send forth his Angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity, and shall cast them into a furnace of fire. There shall be wailing and gnashing of teeth. Then shall the just men shine as the sun in the kingdom of their father. He that hath ears to hear, let him hear." The passage speaks of a kingdom where the good seed is flourishing and bringing forth fruit (v.26) but where the enemy has also sowed tares (so this cannot be the heavenly kingdom). Both continue until the harvest/judgment, and then the eternal kingdom is established. This seems to fit the post-mil understanding of what we were taught to pray for - yes there will be opposition, persecutions, and apostacy, but the good seed will grow and flourish and mature until it is ready.
Yes, all the ages are evil (Galatians 1.4), compared to the age of eternal glory (v.5) which is what I think Paul is trying to say here, not that there are now only 2 ages, with one being this present evil age and the other being "the coming eternal age" (I do not think of eternity as an "age"). Similarly, when Christ was condemning the Jews of His day for their unbelief and called them "an evil and adulterous generation" (Matthew 12.39) and a "wicked generation" (v.45), I do not think He was saying that this was the only wicked, evil, and adulterous generation. So I do not agree that the writers of New Testament Scripture only spoke of two ages/worlds/times/generations. They use these words interchangeably (which is often reflected in our translations), with some writers favoring one term while another uses another, to speak of many "ages": an age before Christ was born ("in the days of Herod the king" -
Matthew 2.2), the age of John before Christ began His ministry (compare
Matthew 3.11-12 with the Matthew 13 passage above, see also
Matthew 11.12: "And from the time of John Baptist hitherto, the kingdom of God suffereth violence..."), the current wicked generation of Jews who rejected Jesus as the Christ ("this generation" - all throughout the Gospels), an age of judgment for that rejection (Matthew 24), "the time of the Gentiles" (
Luke 21.24), and so on.
There is much in Scripture that is partially fulfilled, being fulfilled, and yet to be fulfilled - all at once! This is why, perhaps, you sense a "grogginess of some amils" - trying to put the various layers of fulfillment into two ages requires a certain vagueness at times (blurring some of the prophesies directed separately to Jews and Gentiles, for example, while other prophesies apply to both). When you try to make the amil position more precise, you then must (erroneously in my view) force Scripture into 2 remaining ages. But accepting that there are many ages after Christ comports with many "writers of New Testament Scripture" - Paul, for example speaks of how God has "quickened us together in Christ, by whose grace ye are saved, And hath raised us up together, and made us sit together in the heavenly places in Christ Jesus, that he might show
in the ages [plural of αἰών]
to come the exceeding riches of his grace through his kindness toward us in Christ Jesus." (
Ephesians 2.5-7) And in the next chapter, he states "If ye have heard of the dispensation of the grace of God, which is given me to youward.... Which in other ages [here he uses the Greek word we now usually translate "generations" - i.e. the time or "age" ordinarily occupied by each successive generation) was not opened unto the sons of men, as it is now revealed unto his holy Apostles and Prophets by the Spirit, that the Gentiles should be inheritors also, and of the same body, and partakers of his promise in Christ by the Gospel...." Which brings up back to Colossians 1 (but verses 25-27): "I am a minister, according to the dispensation of God, which is given me unto youward, to fulfill the word of God, the mystery hid since the world began, and from all
ages [again the plural of αἰών], but now is made manifest to his Saints, to whom God would make known what is the riches of his glorious mystery among the Gentiles...."
The kingdom of God is here (see passages such as
Luke 9.27), and it is coming (
Luke 13.29) - it was, in Christ's day, a mustard seed and a pinch of yeast (Matthew 13/Luke 13). But in your two-age amil paradigm, where is this growing kingdom of the God if we are still living in a "present evil age." How can one hope tp see "the fullness of the Gentiles" which the Apostles speak about (
Romans 11.25, cf.
Luke 21.24) happen during a "present evil age"?