Jesus' earliest followers saw no reason they couldn't be good Jews and also his disciples. In the beginning of our faith, all of them were good Jews. It seems to have taken years before anyone thought it possible for a non-Jew to convert to Christianity without first converting to Judaism.
Scripture scholars have been telling us for a long time that the historical Jesus had no intention of founding a church as we know it. As an itinerant preacher, he simply wanted his followers to experience God's kingdom among them: to undergo such a deep change in their value system that they'd be able to surface God working effectively in their everyday lives. He delivered his message in the context of Judaism, to people who followed the 613 laws of Moses. All males were circumcised, most showed up at the local synagogue on Saturday, no one even thought of eating a BLT.
When "radicals" like Paul of Tarsus started to lift the faith of Jesus from its original Jewish context and present it to people who didn't know a lox from a bagel, without insisting they acquire that knowledge, they met fierce opposition from many Jewish Christians. (Some historians, like Garry Wills, are convinced these conservative Christians eventually turned Paul and Peter over to the Roman authorities who killed them.)
Of course, Paul didn't take such an unprecedented step without surfacing a biblical text to defend it. Today's first reading contains that text: "Abraham put his faith in Yahweh, who credited it to him as an act of righteousness."
The Apostle knew two things that slip by many of us. First, "righteousness" is the biblical way of saying we're doing what God wants us to do. Joseph, for instance, in Matthew's gospel is described as a "righteous man." Years ago, the Israeli Knesset designated Oscar Schindler, the hero of Schindler's List, a "righteous Gentile." Both were regarded as carrying out God's will, even if one refused to divorce a pregnant wife, and the other wasn't even a Jew.
Second, though Abraham lived at least 400 years before Moses received Yahweh's law on Mt. Sinai, most Jews, during Paul's lifetime, identified righteousness with keeping those 613 regulations. The Apostle asks, how can righteous come from keeping the law when, centuries before the law came into existence, Abraham was called righteous? Gentiles who want to follow Jesus can share in Abraham's righteousness by simply having faith in God.
As our transfiguration gospel shows, faith in Jesus as God is at the heart of true faith. He stands in the middle of Moses and Elijah - the law and the prophet - a biblical symbol for the Bible. Luke, like Paul, believes faith in, and imitation of the risen Jesus is all God expects of anyone.
That's why Paul, in today's Philippians pericope, is so uptight with those Christians who've made their God their stomach. He's obviously talking about anyone who claims to be a disciple of Jesus, but who still believes salvation comes from keeping the Mosaic dietary regulations. Instead of daily dying and rising with Jesus, these "enemies of the cross of Christ" are concerned only with the kind of food they eat.
Perhaps we at times should also be concerned with lifting the faith of Jesus from the Roman Catholic context in which we received it. What does God actually expect of us? After all, even the historical Jesus regarded people as righteous who knew nothing about the papacy, canon law, catechisms or the hierarchy. I wonder who Paul would regard as enemies of the cross of Christ today?