V.6 Suddenly God brings in the Lord Jesus; without identifying Him. One who will be able to bring Israel back to God.
V.14 In the tribulation God will be only acting in judgment on Israel. But God is not finished with Israel. The punishments will increase in severity.
V.15-17 They gladly listen to false teachers when they get away from the Lord. So do believers, Satan has many false teachers today.
V.18-21 And they turn to more wickedness, when their heart is hardened. The last sentence means that God will punish them still more.