What struck me here is that it is possible to have a zeal for God and be lost. So they are not saved. They have zeal for God. They are, in fact, part of the chosen Jewish people. But he prays that they would be saved.
True knowledge is necessary for salvation.
They have zeal. But it is not rooted in knowledge. Zeal is important. But without knowledge it does not lead to salvation. That is what this writer wants you to do.