John Chrysostom

"But watch thou in all things, endure affliction." It was for this therefore, that he foretold these things; as Christ also toward the end predicted that there should be "false Christs and false prophets"; so he too, when he was about to depart, spoke of these things. "But watch thou in all things, endure affliction"; that is, labor, preoccupy their minds before this pestilence assails them; secure the safety of the sheep before the wolves enter in, everywhere endure hardship. "Do the work of an evangelist, make full proof of thy ministry." Thus it was the work of an evangelist that he should endure hardship, both in himself, and from those without; "make full proof of" that is, fulfill "thy ministry."