Verses 6 and 7 are an important pair. There is a contrast the destruction and the eventual restoration of Israel. The iniquities are contrasted with the eventual turning to believe, and the destructions and scattering are contrasted with the both the restoration in the flesh, and the restoration to the lands of inheritance.
Jacob's point here is to set up a paradigm that he will be able to transfer from the Jews of the Old World to his own people. By contrasting the very "iniquitous" Jews (who would destroy Jerusalem and later crucify their Messiah) with the repentant and believing Jews who would be restored in flesh and lands, Jacob creates a very important sin/repentance example. The example shows the extent of the mercy of God, and the ability to return even from such a far departure. Against this backdrop, Jacob will discuss his own peoples prophecies iniquities, separation, and prophesied return.