Is Christianity based on older myths?

[Mister Agenda]

1: There aren't very significant similarities between Mithras/Osiris and Jesus

There are significant similariities, but the zeitgeist people tend to exaggerate them. Isis wasn't exactly a virgin, for instance, though getting pregnant by her dead husband might qualify as divine impregnation by a holy ghost.

2: The Egyptian religion was enforced by the state, same with many other religions, while Christianity grew despite the state.

Up to the point where Christianity, too, became a state-enforced religion, and the bulk of its growth occurred during the time it was a state religion.

3: Jesus was a real person, there is practically no debate amongst scholars of antiquity.

I'm inclined to agree, though there is so little evidencial support of it, that certainty on grounds of evidence is entirely unjustified.

Even if we were to exclude the Biblical sources, there are many others such as Tacitus et al.

All of which are hearsay and none of which are actually contemporary.

This before we even try to explain the rapid rise of Christianity if there were no Christ.

Though I estimate the odds of a historical Jesus the Gospels are based on having existed at slightly more than 50%, all you need to explain the rapid rise of Christianity is Paul, who never met Jesus in person and seems unaware of most of the Gospel stories about him.

---

"Christus, the founder of the [Christian] name, was put to death by Pontius Pilate, procurator of Judea in the reign of Tiberius. But the pernicious superstition, repressed for a time, broke out again, not only through Judea, where the mischief originated, by through the city of Rome also." Tacitus Annals XV, 44, AD ~115. (Even this source demonstrates CHristianity had spread from Judea to Rome before the time of writing)
Tacitus was a Roman historian and senator, writing merely some 60-70 years after the event. Hardly likely he is mistaken

That sure would be relevant if any of us had disputed the existence of Christians in Rome in the time of Tacitus.

Christianity had reached Rome by about AD 50, and before AD 100 had established over 40 international bases.

"Many of these Early Christians were merchants and others who had practical reasons for traveling to northern Africa, Asia Minor, Arabia, Greece, and other places.[4][5][6] Over 40 such communities were established by the year 100,[5][6] many in Anatolia, also known as Asia Minor, such as the Seven Churches of Asia. By the end of the first century, Christianity had already spread to Rome, India, and major cities in Armenia, Greece and Syria, serving as foundations for the expansive spread of Christianity, eventually throughout the world."
http://en.wikipedia.org/wiki/Early_cente...anity#Rome

All of which makes it unremarkable that Christianity could spread from Jerusalem to Rome in less than fifty years. People were making the trip all the time. There were probably Christians in Rome before 40 AD.