Now that's an interesting question that will not be answered because it actually deals with the issue at hand.
"WHY WOULD GOD DEVISE A THEOLOGY THAT HE WOULD HAVE KNOWN FOR AN ABSOLUTE FACT WOULD BE IMPOSSIBLE TO IMPLEMENT FOR FIFTEEN HUNDRED YEARS?"
Let me give you six verses that can answer the question.
Gen. 15:16, "But in the fourth generation they shall come hither again: for the iniquity of the Amorites is not yet full."
For 1500 years (Psalms 106:15) "And he gave them their request; but sent leanness into their soul."
For 1500 years (Jhn 1:5) "And the light shineth in darkness; and the darkness comprehended it not."
During that 1500 years (Acts 14:16-17) "Who in times past suffered all nations to walk in their own ways. Nevertheless he left not himself without witness, in that he did good, and gave us rain from heaven, and fruitful seasons, filling our hearts with food and gladness.
2Pe 3:9, "The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance."
Finally, after 1500 years the truth that salvation is by grace through faith alone was again revealed (Gal. 4:4) "But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,"
I have asked that questions on a number of threads a number of times. I have yet to receive a suitable response, because if a person is intellectually honest they realize that there is no response.
The only real response I have ever received was from one poster who opined that had he lived in medieval Europe, he would have made certain that his family owned one, even if they had to sacrifice. The reality is that the "average" person in medieval Europe lived in poverty and would not earn enough money in their lifetime to purchase a Bible. And aside from this, even if they could afford a Bible, it was not as if you could go down the street to the neighborhood bookstore and buy one, they were hand inscribed and it took years to produce a single volume. But even if a person had the money (and remember that in those days you couldn't just borrow the money) and the time to wait (which is a negligible proposition because the average adult who had amassed the money to purchase a Bible wouldn't still be alive by the time his order was complete -- if a king or nobleman put in an order, your's would get "bumped") the fact still remains that the person in question would probably be illiterate.
In short, to devise a plan of Salvation that is so unattainable would be totally inconsistent with God's Omnipotence and Love.