1 Corinthians 16:13

Epistle of Ignatius to the Tarsians

I therefore, the prisoner of Christ, who am driven along by land and sea, exhort you: "stand fast in the faith,"[2]

Shepherd of Hermas Vision First " And while she spoke to me, two men appeared and raised her on their shoulders, and they went to where the chair was in the east. With joyful countenance did she depart; and as she went, she said to me, "Behave like a man,[34]

The First Epistle of Pope Fabian

And in another place: "Watch ye, and pray, and stand fast in the faith. Quit you like men, and be strong. Let all things be done with charity."[3]