The Christians citing Acts to "prove" Paul thought of Jesus as a real person aren't really helping. Acts was written by someone else who did think of Jesus that way, so of course he's going to depict his hero as doing so.

The question seems to be inspired by a version of the fringe Jesus Myth hypothesis, namely the one presented by amateur writer Earl Doherty and recently championed by PhD graduate and anti-Christian activist Richard Carrier. Doherty argues that the first form of Christianity didn't believe he was a historical figure at all and imagined he lived in the heavens - in the "sub-lunar celestial sphere", to be precise. According to Doherty, Paul's writings reflect this belief in a purely celestial Jesus and he had no conception of Jesus as an earthly, historical person. Then, Doherty argues, the mythic/celestial Jesus got "historicised" later and turned into a god-man who did things on earth, which is the Jesus we find in the gospels and Acts. The earlier "Celestial Jesus" proto-Christianity then faded away (vanished without trace, actually) and we were left with the historical god-man Jesus of the gospels. 

While this idea is strangely popular amongst internet atheists who have never studied the material, pretty much every scholar on the planet thinks it's hogwash.

To begin with, while Paul's letters put far more emphasis on what he believed about the risen Jesus and very little on the earthly Jesus he never met, there are clear references in his writings which make it obvious that he believed that Jesus had been a man, had taught, had been executed and had family and friends. It is extremely difficult for the "Jesus Myth" proponents to make these references go away.

Paul says Jesus was born as a human, of a human mother and born a Jew (Galatians4:4). He repeats that he had a "human nature" and that he was a human descendant of King David (Romans1:3). He refers to teachings Jesus made during his earthly ministry on divorce (1Cor. 7:10), on preachers (1Cor. 9:14) and on the coming apocalypse (1Thess. 4:15). He mentions how he was executed by earthly rulers (1Cor. 2:8) and that he died and was buried (1Cor 15:3-4). And he says he had an earthly, physical brother called James who Paul himself had met (Galatians1:19). Doherty and Carrier work very hard to try to argue that passages that say he was "born of a woman" actually mean "not born of a woman", but they have failed to convince scholars.

The second flaw in Doherty's thesis lies in his claim that this idea of "fleshly" events happening in some "sub-lunar" celestial realm up in the heavens was a common and accepted concept in the Middle Platonism of the time. He argues that if we look at the way Paul depicts Jesus (once we've argued away all the clear references to him being a human), we see exactly the kind of Middle Platonic conception of a celestial being in a "fleshly" yet non-terrestrial realm. Unfortunately, when he is pressed to provide actual examples of this, he comes up with nothing much to substantiate this claim. In fact, once when a knowledgeable online debater challenged him to provide some evidence that pagans actually believed in a sub-lunar, non-terrestrial realm where gods etc could "take on flesh", get crucified and die etc he admitted that he couldn't do so:

"I get the idea that you have interpreted me as though I were saying: the pagans placed the myths of their savior gods in the upper world, therefore we have good reason to interpret Paul that way. Actually, my movement was in the opposite direction. I have always worked first with the early Christian record, and come to a heavenly-realm understanding of it through internal evidence (supported by the unworkability of an earthly understanding of that record)"

This is an extraordinary admission by Doherty. His book argues that we can read Paul as believing in this "fleshly sub-lunar realm" because this can be found in Middle Platonic thought. But here he admits that he can't produce evidence that this idea existed in Middle Platonism because he's actually getting this whole idea from a reading of Paul that simply assumes this whole "fleshly sub-lunar realm" idea. In other words, this whole central plank of his thesis is based on a priori circular reasoning. The atheist Biblical scholar Jeffrey Gibson has engaged Doherty and his followers in online debate and came away scornfully unimpressed. He noted:

"... the plausibility of D[oherty]'s hypothesis depends on not having good knowledge of ancient philosophy, specifically Middle Platonism. Indeed, it becomes less and less plausible the more one knows of ancient philosophy and, especially, Middle Platonism.

"If you think that this is not the case, please name anyone among the actual and recognized experts in ancient philosophy and/or on Middle Platonism who thinks D's views on what the ancients thought about the way the world was constructed, and who did what where, has any merit."

The final fatal flaw in Doherty's thesis is his contrived idea that there was a "mythic Jesus Christianity" that existed alongside the better known "historical Jesus Christianity" until the latter won the battle for dominance and wiped out any reference to the former. Until Doherty came along and became the first person in about 2000 years to realise what happened.

This is completely implausible. While the idea of Machiavellian early Christians completely erasing all trace of earlier forms of Christianity may appeal to zealots and conspiracy theorists, it simply doesn't square with the evidence. It's true that later "orthodox" forms of Christianity were happy to burn the books of their "heretical" rivals to keep them from infecting the faithful. But this doesn't mean they were also happy to wipe out all trace or mention of these "heresies". On the contrary, they were keen to write long and detailed books explaining why their heretical rivals were wrong and why the orthodox view was right. They often distorted their rivals' ideas when they did this and sometimes the heresy in question had been dead for so long they were confused about precisely what the heretics in question had believed (they just knew they were wrong), but they certainly didn't erase all mention of them. They felt it was important to refute even minor or long dead heresies in as much detail as possible, just in case they rose up again (as some did occasionally).

But Doherty would have us believe that in amongst all these apologetic, anti-heretical literature there is pretty much NO reference to what should have been the biggest and most threatening heresy of all - the heresy that the historical Jesus never existed. Not only would Doherty's supposed "mythic Jesus Christianity" be a major threat to "historical Jesus Christianity" even after it had declined and vanished, it would actually have been THE major threat by merit of the fact that it was the original form of Christianity. Yet we find not a whisper about it in any of this literature. Doherty would have us believe that these writers bothered to condemn tiny and long-extinct heretical sects, yet ignored the elephant in the room and made no mention of this primary threat to their interpretation of Jesus.  

This silence makes no sense.

Unless, of course, this whole "mythic Jesus Christianity" is a figment of Doherty's speculations and didn't exist at all. Then the silence about it in the sources makes perfect sense.

So it's pretty clear why Doherty's thesis gets no traction in the academic sphere and is regarded as a flawed theory by an enthusiastic amateur. The idea that Paul didn't believe that Jesus had been a real, historical person simply doesn't work.

Over 99% of historical scholarship acknowledges that Jesus was a real person. It doesn’t matter if that scholar is liberal or conservative, or Christian, atheist, agnostic or Jewish. The <1% of historians that believe Jesus is a myth are mostly atheists or agnostics. And it’s only the ‘internet infidel’ crowd that takes their arguments seriously.

At least one of the arguments that Jesus mythicists will often push is that Paul was mostly silent about the historical Jesus. Here’s GA Wells, one of the minority voices, who writes:

“Paul’s letters have no allusion to the parents of Jesus, let alone to the virgin birth. They never refer to a place of birth…. They give no indication of the time or place of his earthly existence. They do not refer to his trial before a Roman official, nor to Jerusalem as the place of execution. They mention neither John the Baptist, nor Judas, nor Peter’s denial of his master…. These letters also fail to mention any miracles Jesus is supposed to have worked, a particularly striking omission, since, according to the gospels he worked so many.”

(The Historical Evidence for Jesus, 22)

 

And why didn’t Paul quote Jesus’ praise of celibacy in 1 Corinthians 7? Or why not quote the Sermon on the Mount when Paul was teaching the Romans to bless their persecutors to give his message more authority? (Romans 12:14) Or why did Paul say, “we don’t know how to pray as we ought” (Romans 8:26-27) when Jesus taught his followers how to pray in Matthew 6:8-13?

One of those famous internet atheists, Dan Barker, sides with the Wells, writing:

“The earliest Christian writings, the letters of Paul, are silent about the man Jesus: Paul, who never met Jesus, fails to mention a single deed or saying of Jesus…and sometimes contradicts what Jesus supposedly said. To Paul, Jesus was a heavenly disembodied Christ figure, not a man of flesh and blood.”

 

At first glance, the mythicists seem like they have a point. But there are a few problems here.

ARGUING FROM SILENCE IS USUALLY A POOR WAY TO PROVE YOUR POINT

For starters, arguing from silence is usually a terrible way to argue. For example, Union General Ulysses S Grant says nothing about the Emancipation Proclamation. The famous explorer Marco Polo traveled to China but never mentions the Great Wall. The archives of Portugal do not allude to the travels of Amerigo Vespucci.

An estimated 16,000-60,000 people died in 79 AD due to the eruption of Mt. Vesuvius. But we only hear about this event in a personal letter of Pliny’s. The relative silence of historians we’d expect to mention these events doesn’t cause scholars to doubt their occurrence.

Regarding arguments from silence, philosopher Tim McGrew writes:

“Such arguments from silence are pervasive in New Testament scholarship, but they are tenuous at b (http://best….it)est….it is a risky business to speculate upon the motives of authors for including or omitting various facts. To create an appearance of inconsistency by this device…is methodologically unsound.” (Blackwell Companion to Natural Theology)

 

PAUL’S LETTERS WERE OCCASIONAL

There’s also the fact that most of Paul’s letters were occasional. Paul often wrote to combat error, or to provide specific guidance to churches. So, for example, Paul writes his entire letter to the Galatians to fight the doctrine of the Judaizers. Or there are the specific answers Paul gives about marriage, meat sacrificed to idols, spiritual gifts, and public worship in 1 Corinthians.

And think about it for a minute. If there weren’t some false teachers in Corinth saying there’s no resurrection, the great resurrection teaching in 1 Corinthians 15 would be missing from our Bibles! Jesus’ miracles, parables, virgin birth, arguments with the Pharisees, and so forth weren’t relevant to Paul’s purposes in writing those particular letters.

THE SILENCE OF PAUL…ABOUT PAUL

In his book Did Jesus Exist?, agnostic Biblical scholar Bart Ehrman points out that Paul wasn’t just silent about some historical facts about Jesus, he also didn’t tell us a lot about himself. Like for instance: Who taught Paul? Where did he grow up? What did he do for a living? What did he do during his three years in Arabia or Damascus before meeting with Peter and James in Jerusalem? Or in the following fourteen years? Where did he go? Paul doesn’t tell us in his letters. We only learn about a few of these things from reading Acts.

Wells mentions that we don’t learn about Jesus’ miracles from Paul. But Paul said he had miracles in his ministry, and that was proof he was an apostle. (Romans 15:19, 2 Corinthians 12:12) Does Wells expect us to believe that Paul believed he and the other apostles had miracles, but Jesus didn’t?

THE SILENCE OF OTHER EARLY CHRISTIANS

But we can take it a step further. We have three letters from John, or at least attributed to him. Scholars believe he was writing to combat the proto-gnostics who were saying that sin wasn’t really a thing, and Jesus wasn’t a physical being. (1 John 1:1-3, 8) But the writer of these epistles, who wrote just like the writer of John’s Gospel, (I think they are both written by John, but some scholars debate that) doesn’t mention Jesus turning water into wine, healing a man born blind, feeding the 5,000, walking on water or raising Lazarus from the dead. He doesn’t even quote the words of Jesus from that gospel. Why was the writer of 1-3 John silent about these things? Because they didn’t suit his purposes, not because he didn’t think that they happened.

Furthermore, most scholars believe that the author of Luke’s Gospel is the same author of Acts. Acts is Luke’s sequel. But in Acts, Lukes makes little use of the Jesus tradition he’s obviously familiar with. Clearly the lack of references to Jesus’ teachings in Acts doesn’t show that Luke was ignorant about what Jesus taught!

And what about the writings of some of the early church fathers? 1 Clement, Barnabas, and Polycarp’s letters to the Philippians. These letters fail to mention:

• Jesus’ temptation in the wilderness.
• His parables.
• That he healed the sick and cast out demons.
• That he was transfigured on the mountain.
• That he got into arguments with the Pharisees.
• That he cleansed the temple.
• That Judas betrayed him.
• That Pilate had him crucified.

Do we conclude that these writers didn’t think Jesus existed? No, we don’t. In the case of Polycarp, he quotes Matthew, Mark, and Luke, but these other traditions were not relevant to why he was writing so he fails to mention them.

PAUL’S “SILENCE” DOESN’T PROVE WHAT THE MYTHICISTS CLAIM

Finally, Paul wasn’t silent about the historical Jesus. Paul knows a lot about Jesus. He knows that Jesus was a descendant of David, that:

• He had a mother (Galatians 4:4)
• He was a Jew who lived according to the Law (Gal 4.4)
• He a brother named James and other siblings. (Gal. 1:18–19)
• He had a disciple named Peter and John. (Gal 1:18–2:9)
• He had 12 disciples. (1 Cor. 15:5)
• He had a mission to the Jews. (Romans 15:8)
• He taught on divorce and remarriage. (1 Cor. 7:10–12)
• He taught about giving to support missions. (1 Cor. 9:14)
• He taught about the end of all things. (1 Thess. 4:15)
• He welcomed people. (Romans 15:5, 7)
• He was humble and served others. (Philippians 2:7–9)
• He shared a final meal with his disciples. (1 Cor. 11:23–26)
• He was betrayed. (1 Cor. 11:23)
• He was abused. (Romans 15:3)
• He was crucified at the instigation of the Jews of Judea. (1 Thess. 2:14–15, 1 Cor. 1:23)
• He was buried. (1 Cor. 15:4)
• That it was believed that he appeared to his disciples after his death. (1 Cor. 15:5–8)

But Paul’s main focus was Christ and him crucified. (1 Corinthians 2:2) It is what the cross and resurrection accomplish for the believer is what Paul is obsessed with. He’s interested in unpacking that teaching to the young churches. But his alleged silence isn’t a good argument to think that Jesus didn’t really exist. Bart Ehrman, no friend of traditional Christianity concludes that the so-called silence of Paul is a really bad way to argue, writing:

“What do these silences show? They do not show that these authors did not know about the historical Jesus, because they clearly did. If anything, the silences simply show that these traditions about Jesus were not relevant to their purposes…What we can know is that Paul certainly thought that Jesus existed. He had a clear knowledge of important aspects of Jesus’s life—a completely human life, in which he was born as a Jew to a Jewish woman and became a minister to the Jews before they rejected him, leading to his death. He knew some of Jesus’s teachings. And he knew how Jesus died, by crucifixion. For whatever reason, that was the most important aspect of Jesus’s life: his death. And Paul could scarcely have thought that Jesus died if he hadn’t lived”.

 

(Did Jesus Exist? The Historical Argument for Jesus of Nazareth, p. 145)

While I’ve disagreed with Dr. Ehrman on a lot of things (as anyone who follows me on here can attest) I have to offer a hearty amen here.