They are no consistent and are not firsthand.
Not firsthand: they are all written in Greek not in Aramaic, they reference an event that hasn't happened yet, none of the apostles (don't even try Luke) were literate, the Gospels show sophisticated use of writing techniques and references to myths the apostles would not have heard, stuff is missing that should be in there, exact copies of text are found word for word across them, you can see traces of the arguments that were going on decades later, and the godpels dont even claim to be first hand. Oh and the geography of Mark is totally off.
They are not consistent: go ahead and answer these questions
- Where was Jesus born? 2. Why did the family go to Bethlehem? 3. Tell me his lineage. 4. What year was he born? 5. How many trips to Jerusalem did he make? 6. How long was the ministry? 7. When did the curtain rip? 8 Who exactly went to the cave? 9. Was the rock there or was it moved? 9 What did they see at the cave? 10. How long was Jesus back on earth for? 11. Was the trial brief like Mark or sitcommish long like in John? 12. What did he say on the cross? 13. What did he say on the way to the cross? 14. What animal(s) did he ride? 15. Did he rebuke the leaper at the temple or not?
These are all off the top of my head. There are hundreds out there.