Is Jesus a myth?

[FightingFat]

I am very interested in the arguments surrounding the historicity of Jesus. I am particularly struggling in a debate I am having with someone who could be described as Gnostic. The discussion is based around syncretism, where direct equivalents to the annunciation, virgin birth etc have been discovered in Egyptian mythology.
I have had some success debating with other Christians as to the validity of our faith, but I haven’t really faced this sort of argument before- ie that Jesus is a myth and that Josephus and similar sources have beed altered by Christians after the event to reflect proof of his existence.

I would really appreciate some help and guidance in this debate.

 

[Jim_Blackburn]

In his book The Historical Reliability of the Gospels Craig Blomberg cites Graeco-Roman and Jewish sources in addition to Christian sources of early writings attesting to the historical existence of Jesus.

See also:
Is there any historical evidence that Jesus existed?
How do we know Jesus really died on the cross?
Convincing a Catholic that Jesus really existed…