Why did God allow the temple and Jerusalem to be destroyed in A.D. 70?
God allowed it because Israel continued rejecting the Old Testament promises of the King and Kingdom, rejected their Messiah and King, and failed her role as evangelist. Forty years after Pentecost, God sovereignly permitted the Roman army under Titus to destroy the temple and Jerusalem, dispersing the Jews, and turned to the Gentiles in the Age of Grace.
Les explains that after the crucifixion and Pentecost, Israel kept rejecting the Old Testament promises of the King and the Kingdom, along with her calling to be the evangelist to the pagan world. Spiritually she went downhill, and in A.D. 70—forty years after Pentecost or the crucifixion—God sovereignly permitted the Roman army under Titus to destroy the temple, Jerusalem, and uproot the Jews into dispersion. This happened because they rejected the promises, their Messiah, and their King. God took away their temple and religion, then turned to the Gentiles in the Age of Grace. Les also points to Daniel 9, where 490 years are determined upon the people, 483 were consummated, and then there is a break, with the final seven years addressed later in the chapter.