Luke (Apostle) recounts how Jesus showed himself through "infallible proofs."
Book of Acts, 1:1-3 (Codex Sinaiticus)
τον μεν πρωτο λογον εποιηϲα μην περι παντω ω θεοφιλε ων ηρ ξατο ο ιϲ ποιειν τε και διδαϲκιν αχρι ηϲ ημεραϲ εντιλα μενοϲ τοιϲ απο ϲτολοιϲ δια πνϲ αγιου ουϲ εξελεξα το ανελημφθη οιϲ και παρεϲτη ϲεν εαυτον ζων τα μετα το παθει αυτον εν πολλοιϲ τεκμηριοιϲ δι η μερων τεϲϲερα κοντα οπτανο μενοϲ αυτοιϲ κ(αι) λεγων τα περι τηϲ βαϲιλειαϲ του θυ
The former discourse I made, O Theophilus, concerning all things that Jesus began both to do and to teach, till the day in which he was taken up, after he had, through the Holy Spirit, given commandments to the apostles whom he had chosen: to whom he also showed himself alive, after he had suffered, by many infallible proofs, appearing to them for forty days, and speaking of the things pertaining to the kingdom of God.