A Song of Ice and Fire
Post updated here.
Scot McKnight asks the question, and points to Jimmy Dunn's new book for a possible answer:
"It was as an Israelite that Paul was an apostle to the Gentiles, and as an apostle to the Gentiles Paul was fully an Israelite. Paul was no apostate; he was an apostle of Christ and for Israel. Dunn also develops the eschatological perspective on Paul, namely that the curtain of history was coming down and he was playing a role in that drama. He appeals to 1 Corinthians 4:9, Romans 11:13-15..."This is true enough as stated but only gets at part of the issue, and perhaps not the more significant one. Whenever scholars ask, "Was Paul an apostate?", or "Was Paul a convert?", or "Was Paul sectarian?", seldom enough emphasis falls on the reception of Paul's gospel, which is what really matters. Apostates naturally think they're faithful, and often show themselves brilliantly capable of using tradition to justify whatever they need. The proof of the pudding is in the eating, or in the reception, and Paul went against enough opposition and hostility to convince other scholars, contra Dunn, that it's perfectly reasonable to speak of Paul's conversion more than calling, sectarianism instead of renewal, and apostasy trumping apostolateship.