"just as they were handed down to us by those who were eyewitnesses"....

Luke's information came from eyewitness account.
Matthew, John Mark, and John the apostle Walked with Christ and were eyewitnesses. That's how the Gospel becomes Eyewitness account. The information comes from those who were with Christ.

Flavius forged???? By who?? cmon Hotep where are you gettin this from?

And to retort Flavius is not the only Non-Christian source that historical evidence agrees with the New Testament.

Tactius- The first-century Roman is considered one of the more accurate historians of the ancient world.

Suetonius- Was chief secretary to Emperor Hadrian (reign 117-138)

Josephus- A historian, working under the auspices of Emperor Vespasian. His Antiquities dates to the early 90s a.d.

Thallus - Wrote around 52 a.d. fragments of his works are still existant.

Pliny the younger- Young roman author and administrator.

Emperor Trajan- Replys to Pliny in a letter on how to punishs Christians

Emperor Hadrian- Christian Historian Eusebius(265-339)records a letter to Minicius Fundanus, the Asian proconsul.

The Talmud- Talmudic writings between 70 and 200 AD

there are many more.

This quote comes from the Baker Encyclopedia of Christian Apologetics

" The first step in establishing the historicity of the New testament id to show that the NT documents have been accurately transmitted from the time of their original composition. This is demostrated in the article New testament Manuscripts.
That second step is to show that they were written by reliable eyewitnesses or contemporaries of the events. For this see New testament, Dating Of. Contrary to critics , there is more evidence for the historicity of the life, death, and resurrection of Christ than any other event from the ancient world.