Right with the exception of Mark's gospel which is independent from Paul. Last time I looked, the non Christian sources' authenticity (Josephus and Tacitus) are debated heavily, and it's been a long time since I've looked at that so I don't know the newest research there.
If you are interested in this, there are hundreds on books on "the historical Jesus" (distinguished from the Jesus of faith). The Oxford Handbooks and Cambridge Companion series are great and approachable or you can go absolutely bonkers with this 3300 page tome. https://libgen.is/book/index.php?md5=D597337E74CEC5AA08EB9280D05BE570. Also of note, Crossley and Miles approach historical Jesus studies through class conflict in an approachable and easy read: https://libgen.is/book/index.php?md5=78F35D96CD1497BED0C59C5DD2ACC50F
Right with the exception of Mark's gospel which is independent from Paul. Last time I looked, the non Christian sources' authenticity (Josephus and Tacitus) are debated heavily, and it's been a long time since I've looked at that so I don't know the newest research there.
If you are interested in this, there are hundreds on books on "the historical Jesus" (distinguished from the Jesus of faith). The Oxford Handbooks and Cambridge Companion series are great and approachable or you can go absolutely bonkers with this 3300 page tome. https://libgen.is/book/index.php?md5=D597337E74CEC5AA08EB9280D05BE570. Also of note, Crossley and Miles approach historical Jesus studies through class conflict in an approachable and easy read: https://libgen.is/book/index.php?md5=78F35D96CD1497BED0C59C5DD2ACC50F