Is Jesus just a repackaging of the pagan cults of Mithras and Osiris, just like Xmas is to the Yule?

Question

http://home.earthlink.net/~pgwhacker/ChristianOrigins/

http://www.near-death.com/experiences/origen048.html

"When we say that the Word, who is the first-birth of God, was produced without sexual union, and that He, Jesus Christ, our Teacher, was crucified and died, and rose again, and ascended into heaven, we propound nothing different from what you believe regarding those whom you esteem sons of Jupiter." [Justin Martyr, First Apology, 21]

Answer 1

Of course. Christianity is based on many Pagan practices.

Answer 2

No, we have written eyewitness accounts of Jesus' life, death, and resurrection.

There are also authentic Christian and non-Christian writings going back to the first and second centuries that tell of the early Christian Church.

With love in Christ.