Is the story of Jesus' life based on pagan myths?

Skeptics occasionally allege that the accounts of Jesus' life, death and resurrection were copycats of pagan gods and myths. The following articles are all offsite.

General articles (offsite)

Glenn Miller has a multi-part article covering:

Was Christianity influenced by ancient pagan mystery religions? by Ronald Nash

Mithras (offsite)

Osiris (offsite)

Dionysus (offsite)

Related articles (offsite)