From the book I'm finishing, A New Perspective on Hebrews: Ways That Never Parted. This paragraph relates to Hebrews 6:1-2.
"... It is at this point that we see the great difficulty of supposing a strictly Jewish audience for Hebrews. A Jew would not learn of the need to repent for sins when they began to learn about the Messiah. For a Jew, such teaching would not be part of 'the beginning word about the Christ' but a matter of teaching from childhood. Repentance was similarly a fundamental category within Judaism. The need for “faith upon God” was an overwhelmingly basic Jewish category irrespective of basic teaching about the Christ. We can make the same observation with regard to the presence of resurrection and judgment on the list. It is of course possible that a group of Diaspora Jews might have had divergent beliefs on such things, for such beliefs were not uniform among Jews. Nevertheless, these were basic Jewish beliefs, not distinctively Christian ones.
Before the revisions of the seventies, it was easy to miss how strange a list Hebrews 6:1-2 would be if it were directed toward a Jewish audience. Now, after the new perspective, it is difficult to imagine them directed toward a Jewish audience at all. Only Gentiles would have experienced conversion to Christian Judaism as a change of religion. Faith in God, repentance of sins, belief in resurrection and judgment simply would not have been part of some 'beginning word of Christ' for a Jewish believer! On the other hand, they would be very appropriate for a Gentile convert to the God of Israel."