15 And he said to them: Go ye into the whole world, and preach the gospel to every creature. 16 He that believeth and is baptized, shall be saved: but he that believeth not shall be condemned. 17 And these signs shall follow them that believe: In my name they shall cast out devils: they shall speak with new tongues. 18 They shall take up serpents; and if they shall drink any deadly thing, it shall not hurt them: they shall lay their hands upon the sick, and they shall recover.
Gregory: Are we then without faith because we cannot do these signs? Nay, but these things were necessary in the beginning of the Church, for the faith of believers was to be nourished by miracles, that it might increase. Thus we also, when we plant groves, strong in the earth; but when once they have firmly fixed their roots, we leave off irrigating them.
Holy Church does every day in spirit what then the Apostles did in body; for when her Priests by the grace of exorcism lay their hands on believers, and forbid the evil spirits to dwell in their minds, what do they, but cast out devils?
And the faithful who have left earthly words, and whose tongues sound forth the Holy Mysteries, speak a new language; they who by their good warnings take away evil from the hearts of others, take up serpents; and when they are hearing words of pestilent persuasion, without being at all drawn aside to evil doing, they drink a deadly thing, but it will never hurt them; whenever they see their neighbours growing weak in good works, and by their good example strengthen their life, they lay their hands on the sick, that they may recover.
And all these miracles are greater in proportion as they are spiritual, and by them souls and not bodies are raised.
Scripture from the Douay-Rheims Bible. Commentary from St. Thomas Aquinas, Catena Aurea, Vol. II (London: Rivington, 1842).