Beginning with Moses and all the Prophets, he explained to them what was said in all the Scriptures concerning himself…Then their eyes were opened and they recognized him, and he disappeared from their sight. They asked each other, “Were not our hearts burning within us while he talked with us on the road and opened the Scriptures to us?”
–Luke 24:27, 31-32 (NIV)–

Now there was about this time Jesus, a wise man, if it be lawful to call him a man; for he was a doer of wonderful works, a teacher of such men as receive the truth with pleasure. He drew over to him both many of the Jews and many of the Gentiles. He was the Christ. And when Pilate, at the suggestion of the principal men amongst us, had condemned him to the cross, those that loved him at the first did not forsake him; for he appeared to them alive again the third day; as the divine prophets had foretold these and ten thousand other wonderful things concerning him. And the tribe of Christians, so named from him, are not extinct at this day.
–Josephus, Antiquities of the Jews 18.3.3–
–“The Testimonium Flavianum”–
(94 A.D.)

They were accustomed to meet on a fixed day before dawn
and sing responsively a hymn to Christ as to a god.
–Pliny, Letters 10.96-97–
(110 A.D.)

Christus, from whom the name had its origin,
suffered the extreme penalty during the reign of Tiberius
at the hands of one of our procurators, Pontius Pilatus.
–Tacitus, Annals 15.44–
(116 A.D.)