38. And it is not fitting to boast at the casting forth of the demons, nor to be uplifted by the healing of diseases: nor is it fitting that he who casts out devils should alone be highly esteemed, while he who casts them not out should be considered nought. But let a man learn the discipline of each one and either imitate, rival, or correct it. For the working of signs is not ours but the Saviour's work: and so He said to His disciples: "Rejoice not that the demons are subject to you, but that your names are written in the heavens [1071] ." For the fact that our names are written in heaven is a proof of our virtuous life, but to cast out demons is a favour of the Saviour who granted it. Wherefore to those who boasted in signs but not in virtue, and said: "Lord, in Thy name did we not cast out demons, and in Thy name did many mighty works [1072] ?" He answered, "Verily I say unto you, I know you not;" for the Lord knoweth not the ways of the wicked. But we ought always to pray, as I said above, that we may receive the gift of discerning spirits; that, as it is written [1073] , we may not believe every spirit.'