Because what is currently accepted as being the oldest remaining portion of text from the Gospels is P, a fragment of the Gospel of John from about 125 C.E., or no earlier than the second century.
Sest praegu peetakse evangeeliumide teksti vanimaks säilinud osaks P, Johannese evangeeliumi fragmenti umbes aastast 125 m.a.j. ehk siis mitte varasemast ajast kui teisest sajandist.