Many Christian apologists argue that Christianity was an original religion. I haven't yet read N.T. Wright's The Resurrection of the Son of God, but I took his class on the resurrection when I was at Harvard. His argument was that first century Judaism did not expect the Messiah to rise from the dead. When a Messianic leader died, Wright argued, the movement folded right along with him. Consequently, for Wright, the only possible explanation for the origins of early Christianity is Jesus' resurrection. As far as Wright is concerned, the early Christians had to get that idea from somewhere, and they got it from its actual occurrence. Wright regards Christianity's alleged originality as evidence for its truth-value.
In some circles of New Testament studies, there are still academics who claim that Christianity borrowed its ideas from mystery religions, which believed in a dying and rising god. Other scholars counter that this is not entirely accurate, for Christianity came before certain mystery religions (e.g., Mithraism), plus there are huge differences between the two (see Eric Snow's Is Christianity a Fraud?). Many Christian apologists tend to go with the latter approach, since they want Christianity to be original. Maybe that's because they feel that an original idea has to be accounted for somehow, which opens the door for them to say, "God did it!" When a religion is just a copycat of another belief system, however, they can't really claim that, at least not as convincingly.
Over the last few days, two issues have gotten me to think about the originality of Christianity. One is a recent archaeological find. According to the New York Times, "A three-foot-tall tablet with 87 lines of Hebrew that scholars believe dates from the decades just before the birth of Jesus is causing a quiet stir in biblical and archaeological circles, especially because it may speak of a messiah who will rise from the dead after three days" (see here). Even conservative Christian scholar Ben Witherington accepts its authenticity (see The Death and Resurrection of Messiah--- written in stone). What's this do to N.T. Wright's argument that Jesus' resurrection is true on account of its originality? It looks like others were expecting a Messiah who'd rise from the dead (assuming Israel Knohl is interpreting the stone correctly)!
Second, on my Christian internet dating site, a few of us are going through Kay Arthur's inductive Bible study on the Book of Colossians. We're in Colossians 1 right now. Colossians 1:15-17 states the following about Jesus: "He is the image of the invisible God, the firstborn of all creation; for in him all things in heaven and on earth were created, things visible and invisible, whether thrones or dominions or rulers or powers-- all things have been created through him and for him. He himself is before all things, and in him all things hold together" (NRSV).
Philo of Alexandria was a contemporary of Jesus who lived in Alexandria, Egypt, and he tried to reconcile Judaism with Greek philosophy. The Greeks had a concept known as the logos, which many of them defined as the rational order of the universe. Well, take a look at Thomas Tobin's summary of Philo on the logos, and tell me if it sounds familiar (source: The Anchor Bible Dictionary):
"The logos was the image of God, the highest of all beings who were intellectually perceived, the one closest to God, the only truly existent (Fuga 101). This image, the logos, also served as the paradigm or model for the ordering of the rest of the universe (Somn 2.45). The logos was an image in a twofold way, a reflection of the truly existent God above and a model on the basis of which the rest of the universe below was ordered. The logos was the archetypal idea in which all of the other ideas were contained (Op 23–25). But the logos was not simply the image or paradigm according to which the universe was ordered, it was also the instrument (organon) through which the universe was ordered (Cher 127; Spec Leg 1:81). The logos was both the power through which the universe was originally ordered and the power by which the universe continued to be ordered. Philo called these two aspects of the logos the Creative Power and the Ruling Power, and he connected the first with the name Elohim (God) and the second with Lord (kyrios), the Greek word used to translate Yahweh in the LXX (Vita Mos 2.99–199). Other terms used by Philo to refer to the logos are the First-Begotten Son of the Uncreated Father (Conf 146; Somn 1.215), the Chief of the Angels (Heres 205), the High Priest of the Cosmos (Fuga 108), and the Man of God (Conf 41, 63, 146). What was common to all of these designations of the logos was the intermediate role that the logos played between the transcendent God and the rest of the universe."
Philo's logos was a reflection of God, an intermediary between God and man, the instrument of creation, and God's begotten son. Sound familiar? No wonder John 1:1 calls Jesus the logos! Could Greek philosophy have exercised influence on New Testament understandings of Christ?
How cultural is Christianity? Let's take the topic of the resurrection in the last days. In the synoptic Gospels, Jesus talks about it. The Hebrew Bible, however, does so rarely. As far as it's concerned, dead people go to Sheol, a realm of the dead. Sure, Isaiah and Ezekiel use resurrection as a metaphor for Israel's national restoration (Isaiah 26:19; Ezekiel 37). But the idea of individual resurrection probably took root in Judaism during the time of the Maccabees, when Antiochus Epiphanes was slaughtering righteous Jews for holding fast to their laws (see II Maccabees 7; Daniel 12:2-3). Because most Jews viewed God as good and fair, they thought he had to reward those righteous martyrs in some fashion. They concluded that their reward must be beyond the grave.
But the Hebrew Bible reflects views on the afterlife that were common in its historical contexts, for many ancient Near Eastern cultures (except Egypt) lacked a rigorous concept of the afterlife. And Jesus assumed one of the popular views of his day: bodily resurrection. One can argue that the biblical writings fit right into their cultures.
So what should we do with all this? One Christian writer who was sensitive to these sorts of concerns was C.S. Lewis. According to Lewis, God worked with his people according to what he felt they were ready for. He didn't tell the ancient Israelites much about the afterlife because he wanted them to enjoy him, not focus on what happens after death. Eventually, God took them to the next level: belief in a resurrection.
Lewis also addressed the issue of Christianity's originality. As far as he was concerned, God used cultures to prepare people for Christ. I mean, the New Testament is explicit that the Hebrew Bible foreshadowed Jesus. So why couldn't Greco-Roman culture do the same?
One interesting point is this: Christianity may not have been completely original in the first century, and yet it still spread. People accepted it, for whatever reason. Maybe the conventional defenses of apologists are not as necessary for Christian faith as one might think!