Yes, the Gospels make those claims of Jesus. No other sources. and the earliest of Gospels was written at least a full generation after Jesus's death. John may have been finished after the year 100. The reason that they are reliable is because there are no contemporaneous records of Jesus. There are no other sources that support the claims of the Gospels. At best you have sources that were again written a full generation after he died that barely acknowledged that such a person lived once.
If there were "MANY people" or "MANY witnesses" then why are there no other accounts?
I think you ask a reasonable question. My responses:
1. If all the gospels were written in 90 AD, the difference between 90 and 33 CE is the same as someone today, alive, remembering 1961. There are no counter documents saying the events didn't occur. There was GREAT reason to make counter documents--the Romans and Pharisees were only two of the groups with a big agenda if the historical Jesus was also the Messiah. I date the gospels far earlier, but know many people today alive in 1961 as young adults who could capably write and think now.
2. The sole counter document of any type from the period would be the Talmud, which as it warns Jews to avoid Christianity in the strongest possible terms, actually says Jesus's father wasn't Joseph, Jesus died on a cross at 33 1/2 on Passover, etc.!
3. There were many witnesses, but as a subset, some particular friends and collaborators with Jesus, who dared to write documents that were a death sentence with the Romans and expulsion from Jewish life. 12 different persons or teams of writers wrote documents in the NT. We can reframe your question reasonably to say, "Why did 12 people risk death to promulgate these documents?"
4. That's quite a lot of extant ancient sources for an event(s), 39 documents written by 12 teams, and is more than comparable with any other ancient person--even those who held far more temporal power than Jesus. How many copies of Homer are extant in the oldest copies? How many biographers of Julius Caesar do we have extant from the period?
5. The NT books aren't little birth certificates. They are massive undertakings. I wanted to study Romans better so I memorized it as I studied. In English, Romans is the equivalent of 26-plus Gettysburg addresses! I thanked God I didn't memorize Matthew or even longer books, as friends have done!
6. The extant documents are not only lengthy, detailed, but also, they are highly influential. People have responded to these documents for millennia--and though there is the type of polarization Jesus predicted in the documents, everything up to POTUS and SCOTUS are under scrutiny now for their comparisons to the Bible.
7. Jesus was not Julius, as I wrote. Why should we demand contemporaneous documents of Him? He was a humble "carpenter" who preached then died on a cross. Scholars believe in Bar Kokhba and other "messiahs" readily--and scholars accept the historical Jesus was baptized in water and crucified. Thousands of Jews were baptized and/or crucified, but Jesus is known by name for His
documents.
8. As a
gedanken, I try to use the hypothesis method, to understand your perspective. I believe you think modern scholars get it now, and ancient people were more gullible regarding the Bible. I disagree because a) we see tremendous skeptics confront Christ in the NT and the prophets in the OT b) life spans were brief in the ANE and life was cheap under the Romans, who could crucify practically on a whim, and would toss out unwanted children and spouses. Do you think the ancients who lived in a bloody Israel would readily say, "SURE, some guy came back from the dead!" They saw people dead and buried far more often than modern westerners are exposed to mortality. Rather, we see a very vigorous skepticism everywhere from the Acropolis to the VERY real statement that when Jesus appeared to 500 followers, some trusted Him for salvation and some doubted (honestly) His resurrection.
I find the Bible credible, honest and reliable.