“For we know in part and we prophesy in part. But when that which is perfect has come, then that which is in part will be done away. When I was a child, I spoke as a child, I understood as a child, I thought as a child; but when I became a man, I put away childish things. For now we see in a mirror, dimly, but then face to face. Now I know in part, but then I shall know just as I also am known” (1 Cor. 13:9–12)
The last days of the Old Covenant age–AD 30 to AD 70–were a time of transition. The New Covenant age had broken in, yet it had not yet fully arrived. And until the New Covenant age fully arrived–which would not happen until the Old Covenant system was destroyed (city, temple, covenant, Levitical priesthood, etc.)–the saints only saw the New Covenant realities in part, as through a mirror, dimly. To have a perfected knowledge of the New Covenant age, they would have to experience it.
The Old Testament certainly gave glimpses into the New Covenant age, yet it was a sort of a riddle. Further revelation/information would be needed to bring the saints into a perfected understanding of it. Even the prophets themselves admitted they did not fully understand what they were writing about. For example, after an angel told Daniel about the time of the end, Daniel said: “Although I heard, I did not understand” (Dan. 12:8). The angel then told Daniel, “Go your way, Daniel, for the words are closed up and sealed till the time of the end” (v. 9). Similar statements are made in 1 Peter 1:10-12; 2 Corinthians 3:14–16.
While the apostles knew more than their Old Testament predecessors, thanks to Jesus and the Holy Spirit, even they did not fully understand what the New Covenant age would be like. Sure, the apostles knew cerebrally that the physical temple would be destroyed (Matt. 24:2) and that Christians would be the living temple (1 Pet. 2:4–9). And the apostles also knew, cerebrally, that the physical city of Jerusalem would lose its significance, and that the new, spiritual Jerusalem would replace it (John 4:21; Heb. 12:22). The apostles also knew, cerebrally, that the Old Covenant barriers between Jews and Gentiles would be broken down in Christ (Gal. 3:28; Eph. 2:14). They also knew about the new heaven and earth from Old Testament passages such as Isaiah 65–66. However, until the saints actually experienced the new covenant era, there would remain some murkiness about it. Or, as Paul said, it would be like seeing through a mirror, dimly (1 Cor. 13:12).
Imagine traveling back in time to the year AD 500 and trying to describe to the people of that day things like airplane travel, computers, self-driving cars, the internet, freedom of speech, and so on. Your audiences might grasp the concepts cerebrally, but unless they actually experienced them, they would not have a perfected knowledge of them. This was the case in Paul’s day regarding the new covenant realities. The pre–AD 70 saints saw the new covenant realities as through a mirror, dimly.
However, post–AD 70, Christians now have a “perfected” knowledge of these realities because we experience them. Keep in mind, we will never have 100 percent perfect knowledge because that would require being God. Only God knows everything perfectly. Therefore, that could not possibly be what Paul was referring to in the passage under consideration. Paul was simply referring to a perfected knowledge–experientially–of the new covenant realities through the fulfillment of prophecy.
The fulfillment of the prophecies also confirmed once and for all that Jesus was truly who he claimed to be and that the apostles had chosen wisely and had not run their race in vain.
“The new way was already opened before the old covenant was taken away [in AD 70], but it was hampered until the actual fulfillment, in the destruction of the temple system. Only then would the fullness of the new way be fully disclosed, not by further revelation, but by the verification of history itself. The fall of Jerusalem verified that the new way is the way into the presence of God, and that the first-generation believers had not run in vain with their gospel of the new way. The fall of Jerusalem [also] confirmed the mystery of Gentile inclusion in the spiritual realities of Israel.”