The main passage being discussed from Jewish Antiquities, finished about 93 or 94 A.D., is known as the Testimonium and reads:
“Now there was about this time Jesus, a wise man, if it be lawful to call him a man, for he was a doer of wonderful works, a teacher of such men as receive the truth with pleasure. He drew over to him both many of the Jews, and many of the Gentiles. He was the Christ, and when Pilate, at the suggestion of the principal men among us, had condemned him to the cross, those that loved him at the first did not forsake him; for he appeared to them alive again the third day, as the divine prophets had foretold these and ten thousand other wonderful things concerning him. And the tribe of Christians so named from him are not extinct at this day. “ (Italics added)
(Antiquities, XVIII, 33) a/k/a The Testimonium.
The consensus of serious scholars is that the italicized language was interpolated at some later time by a Christian scribe intent on helping the cause. The language appears almost "cut & pasted" into the overall text.
John P. Meier in "The Testimonium: Evidence for Jesus Outside the Bible", Bible Review June, 1991 wrote:
"Read the Testimonium without the italicized passages and you will see that the flow of thought is clear. Josephus calls Jesus by the generic title 'wise man'. He then proceeds to 'unpack' that generic designation with two of its main components in the Greco-Roman world: miracle working and effective teaching. This double display of 'wisdon' wins Jesus a large following among both Jews and gentiles and presumably it is this huge success that moves the leading men to accuse Jesus before Pilate. Despite Jesus' shameful death on the cross, his earlier adherents do not give up their loyalty to him and so (note that the transition is much better without the reference to the resurrection in the deleted passage) the tribe of Christians has not yet died out."
The Testimonium is useful for rebutting the arguments of some that Jesus never existed and never died on the cross, but a Christian loses credibility by relying on it alone as historical proof that Jesus is the Christ. It is part of the overall collection of historical data which cannot be adequately explained away by skeptics.
The reference to James, the brother of Jesus, in Josephus' Antiquities XX is accepted as authentic by the majority of serious scholars. Among the reasons for accepting the authenticity of of this passage are: (1) a Christian editor would have used complimentary language to describe James and more laudatory language referring to Jesus; (2) The point of Josephus is that Ananus was deposed because he instigated illegal executions of several enemies, including James. However, James is mentioned simply as an example. If a Christian editor was responsible for the inclusion of James we would expect more information to be provided; (3) Josephus' account differs from other Christian accounts of the death of James and, therefore, appears to be independent of Christian tradition (see Clement of Alexandria and Hegesippus in Eusebius Ecclesiastical History 2.23).
Let me add that I'm a believer in Jesus Christ as the risen Lord and the Holy Spirit Himself has born witness to me that this is true. Romans 8:16 The external, historical evidence confirms the truth all believers receive from God's written revelation. As you can see on this thread, there are some believers who see no value in examining this historical data. That's fine. I find this historical data useful in reaching certain types of skeptics, my own brothers and my nephews and nieces included.
Precisley my point. I know of other Christians who hold the same postion you do regarding these writings. Conversely, I have to hold open the posibility that they may not have been tampered with. I highly suspect they have been but then many believers highly suspect they haven't. However, enough doubt exists about their authenticity that its my position its going out on too big a limb to dogmatically use these in serious apologetics. Thank you for your honesty.