Christ is a recycled myth.
The objection, in full
The story of a dying-and-rising god born of a virgin, performing miracles, and being resurrected on the third day predates Christianity by centuries. Horus, Mithras, Dionysus, Osiris, Attis — the parallels are legion. The Gospels were written decades after the alleged events, by partisans, in Greek, far from Palestine. There is no contemporary non-Christian record of Jesus. The simplest explanation is that the figure is fictional, assembled from the mythological raw material of the Hellenistic world.
Did Jesus exist? You probably think this question is settled. It isn't.
or, in plain terms —Jesus is just a copy of older pagan gods.
Even the agnostic scholars say he existed.
I am not a believer, and I will not pretend to be one. I am a historian of late antiquity, and I am here to tell you that the mythicist position is not held by any serious scholar of the period in any major secular university. This is not a matter of religious bias. The faculty of ancient history at Oxford, Cambridge, Harvard, Yale, the Sorbonne — populated overwhelmingly by secular and agnostic scholars — agree that Jesus of Nazareth existed and was crucified under Pontius Pilate. The dispute is over what to make of him, not whether to count him.
The reasons are technical but solid. Paul's letters, written within twenty to thirty years of the crucifixion, refer to Jesus's brother James as a person Paul personally met. The historian Tacitus, writing in 116 AD, mentions "Christus, who was executed by the procurator Pontius Pilate during the reign of Tiberius" — and Tacitus was no Christian. Josephus, a Jewish historian writing in the 90s, mentions Jesus twice, once in a passage that has been interpolated by later Christian copyists but that almost all scholars agree contains an authentic core. The criterion of embarrassment — historians ask why a community would invent details that embarrass them — gives us a crucified messiah, baptism by John (which makes Jesus look subordinate), and a Galilean origin (which made him an unlikely candidate to begin with). You do not invent these details. You inherit them.
The dying-and-rising-god parallels are mostly bogus. Most of the alleged parallels — Horus born of a virgin on December 25th, Mithras crucified and resurrected — are nineteenth-century inventions or massive overreadings of fragmentary evidence. Read the actual primary sources and the parallels evaporate. What you are left with is a Galilean Jewish preacher, executed under Pilate, whose followers shortly afterward began making extraordinary claims about him. That much is history. What to do with it is theology.