How should Gentile Christians relate to their faith differently in light of how profoundly our Jewish heritage shaped it?

Gentile Christians usually think about Gentile Christianity as the normative and normal type of Christian faith and practice. And accordingly we tend to think about the life and the practice of Jewish believers as something special, something that deviates from Christianity. Reading my book may serve to correct that perspective.

You say that many early Christians, despite some anti-Semitic remarks, had an essentially positive regard for things Jewish. How do we know that?

It's mainly an inference, but it is a very direct inference. For example, John Chrysostom says that members of his own Christian community socialized with Jews, visited Jews during their festivals, preferred the local rabbi to the local bishop in matters of marriage, taking of oaths and so on. So, it's quite direct evidence.

There are also some Christian editorial interpolations in Jewish works, such as the Testament of the Twelve Patriarchs, which are very direct in their hope for end-time restoration of Israel and the salvation of the Jewish people.

Before Constantine, Christian worship followed the synagogue pattern of word and prayer. After Constantine, the Temple pattern of priest and sacrifice became the norm. What did we lose in that transition?

We lost the priesthood of all believers. After Constantine, the ordained ministry served in a kind of intermediary function between Christ and his community. The immediacy of the priesthood of all believers was weakened before Constantine, but afterward, it gets lost.

The whole notion of the Eucharist as a sacrifice pushes in the same direction. Because if there is a sacrifice, there have to ...