What do Christians believe? To answer that question it helps to know which group of Christians is answering. But the main theology is common among almost all Christians.
Here it is in a nutshell: Christians believe that if you have faith that Jesus Christ is the divine Son of God who died on the cross for your sins and then was resurrected and ascended into heaven as a flesh-and-blood body, then you will be rewarded in heaven. Christians believe that Jesus was both divine and human.
There are obviously some differences of opinion regarding what you must also believe and how you must act, but these are peripheral to the theology outlined above, which is common among all Christians, regardless of denomination. This view is called orthodox Christianity and any religion that believes differently is called heretical.
But this central belief of Christianity did not come from Jesus Christ. It didn’t even come from the Gospels. It came from Paul. The Pauline Epistles, of which there are 13 in the New Testament, are the sole source of modern Christian theology. And not all 13 of them were actually written by Paul; six of them are attributed to him but were written by someone else, likely after Paul’s death.
The first gospel, The Gospel According to Matthew, takes a view of Jesus that is especially contrary to what Paul wrote of him. Paul and Matthew definitely did not see eye to eye on their respective theologies. And Paul’s theology even runs contrary to what Jesus himself taught.
First, I must offer the disclaimer that what Jesus and his 12 disciples thought or did cannot be known for certain. The gospels and the Book of Acts are all we really have, since there is no independent corroboration of any of the events. And the gospels themselves were only attributed to Matthew, Mark, Luke, and John. They were not actually written by them, but are anonymous. So when I speak of what Matthew says, I’m referring to what he is attributed to have said by his gospel writer.
That said, let’s look at what Jesus taught according to Matthew. Jesus was an itinerant Jewish preacher. He spoke in parables. His disciples were idiots who never got him, (although that view comes mainly from Mark), and most importantly, he was an apocalyptic prophet. He taught that the Kingdom of God would be established on earth by the Son of Man (not himself), and that he would be the one in charge after this happened. His 12 disciples (apparently even Judas Iscariot) would rule the descendents of the Twelve Tribes.
According to bible scholar Bart Ehrman, all Jews of Jesus’ day believed the Messiah would be an earthly king, anointed by God. The Messiah would take up his position on Earth after kicking out or destroying the Romans who were occupying Jewish lands at the time. Jesus taught that this Kingdom of God would be arriving very shortly, within the lifetime of the disciples, (Mark 9:1, 13:30). Jews did not believe that the Messiah would at all suffer a horrible death. He would be more powerful than that.
Paul agreed with Matthew and Mark that the Kingdom of God would happen very soon. He set up his churches in Asia Minor with the idea that their current congregations would be their only congregations until the end came. That’s why the churches became so disorganized; they had no hierarchy or leadership. Paul didn’t think they would need one since they wouldn’t be around that long. Only in the forged epistles that are attributed to Paul does he seem to change is mind about the timing of the End of Time. It was pushed into the future at some unknown time. This view came only after the apostles had started to die off without having witnessed the event. The Gospel of John echoes this same theology, since it was the last gospel to be written and the original apostles had not yet witnessed the coming Kingdom of God.
But the establishment of the Kingdom of God on Earth is about all that Paul and Matthew agree on regarding theology. Paul teaches that the only road to Salvation is through Jesus’ death and resurrection. Paul adamantly believes that the Jewish Law does not apply and, in fact, might even hinder one’s Salvation because adhering to Jewish practices such as circumcision would diminish your faith in what actually matters, Jesus’ atonement for sins through his death and resurrection. Paul claimed that Jesus was divine.
But is that what Jesus, himself, taught? Not according to Matthew and the other gospels. Jesus was thoroughly Jewish. He preached that one must keep the Law (Matthew 5:18). To earn a place in heaven, Jesus preached that one must obey the Law, and especially the law about loving God above all else and to love your neighbor as you do yourself. Jesus never taught about his own divinity in Matthew. Like Jesus, Matthew was a Jew who believed in keeping the Mosaic Law, and his gospel is full of this message.
Paul, on the other hand, was a converted Jew who believed that Salvation could only be obtained by a belief in Jesus, that keeping the Mosaic Law was not necessary, and possibly even harmful. Paul’s theology was passed along to all those who heard his message. But it wasn’t the only message being taught. The Ebionites were a group of early Christians who believed that in order to be a good Christian, you must first be a good Jew. Gentiles who wanted to become Christian first had to be circumcised and start following Mosaic Law. The Ebionites were not a minor offshoot of orthodox Christianity, for orthodoxy had not been established yet. It was a mainstream theology. Ebionites believed that one’s adherence to the Law was necessary for Salvation. They also believed that Jesus was not divine, but fully human. They denied his resurrection. They believed that Jesus was a prophet, chosen by God, and that his teachings are what is important. The Ebionites had their own sacred manuscripts that supported their theology, though they also liked Matthew.
Other early Christians believed pretty much the opposite, that Jesus was divine and not at all human. Some believed Jesus could, if he wanted to, take on any form. Some even claimed Jesus sometimes appeared in the form of an animal. Some early Christian theologies taught that the God of Jesus was not the same as the creator god of the Jews.
Others, such as the Gnostics, were more like pagans, believing in many deities, but also believing that Jesus was chosen to deliver the message, or knowledge, of how one could escape the body that is imprisoning the spirit within.
But the theology that became orthodox, most likely because it was centered on Rome and was adopted by Emperor Constantine, claimed that Jesus was both completely human and completely divine and that one need not accept or follow Jewish Law to be a Christian and gain Salvation. In other words, the theology that would later dominate Christianity, and be called orthodox by its followers, was the theology espoused by Paul. And, as I’ve just described, the theology of Paul was not the same as that of either Matthew or of Jesus himself.
For that reason, maybe Christians should rename themselves Paulianites. The true Christians, according to what Jesus himself supposedly taught, were the Ebionites. But they no longer exist, their theology having been eradicated by the Roman Catholics back in the fourth century.
Of course, I’m not espousing the return of the Ebionite theology to replace mainstream Christianity. Whether it’s Orthodox, Ebionite, Marcionite, Gnostic, or any one of dozens of theologies that all claim or claimed to be the true Christianity, they all have one thing in common: They believe in a supernatural god and his son (or prophet) who was sent to save us from sin. It’s all just myth anyway. My point is to show that Christians today believe what they do because of which version of their religion won out; the one with the most power and influence. It didn’t even have to agree with the teachings of Jesus.