2 occurrences across the corpus

1 Enoch

1 Enoch 83:8

And now, my son, arise and make petition to the Lord of glory, since thou art a believer, that a remnant may remain on the earth, and that He may not destroy the whole earth.

NT Apocrypha/Pseudepigrapha

Acts of Paul and Thecla 9:18

Thecla replied to him; I am a servant of the living God; and as to my state, I am a believer on Jesus Christ his Son, in whom God is well pleased; and for that reason none of the beasts could touch me.