If we compare the Bible to biographies of Alexander the Great, we see that a few original fragments of information about Alexander survive, but the main surviving biographies are written about 200 years after his death. From Wikipedia
HERE: “Most primary sources written by people who actually knew Alexander or who gathered information from men who served with Alexander are lost, but a few inscriptions and fragments survive.” Yet experts study and compare the later biographies and draw conclusions about Alexander.
Though no originals of the New Testament manuscripts exist, very early copies do. The earliest undisputed papyrus fragment of a Gospel was discovered in Egypt. This copy was from the book of John, widely believed to be first written by one of Christ’s close disciples. The fragment is dated from 117 to 138 AD. The original is thought to have been written before 100 AD. Christ died around the year 30 AD.
In a letter to a group of believers (1 Corinthians), the Apostle Paul spoke of 500 eyewitnesses who saw Christ after His resurrection (1 Cor. 15:6). Some of the witnesses were still alive when Paul wrote it. This book of the Bible is therefore estimated to be written within about 25 years of Christ’s life.
Those who knew Jesus preached to others. A man named Polycarp is considered a disciple of the Apostle John. Polycarp was acquainted with Papias, who became a church chronicler. Irenaeus and Eusebius, other very early Christian writers, quoted information from Papias. The popes started in line with the Apostle Peter, then to Linus, with the list of popes
HERE. Jesus was not forgotten at any stage of time after His death and resurrection