The passing away of heaven and earth could only take place when all things that had been written (the Old Testament scriptures) had been fulfilled (Mathew 5:17-18). Jesus placed the fulfillment of all that had been written and the passing away of heaven and earth in his generation (Mathew 24, Luke 21). Since the spiritual realities of what the Old Testament prophesied could not be accomplished in the “world of flesh”, there was the need for a new world to fulfill the promises. The reality is, the passing away of heaven and earth was the passing away of what stood in the way of the redemption in Jesus Christ and the New Covenant (Hebrews 9).
The Institute Of Fulfilled Eschatology