The Shepherd of Hermas

For if you stack wine or oil in a cellar, and put among them an empty jar, and again wish to unstack the cellar, the jar which you put in empty you will find still empty. So also the prophets who are empty, when they come to the spirits of just men, are found out to be such as when they came.

You have the life of both the prophets. Test, then, from his life and deeds, the man who says that he is inspired.

But believe yourself in the Spirit which comes from God and has power, but have no faith in the spirit which is from the earth and empty, because there is no power in it, for it comes from the devil.

Hear, then, the parable which I will tell you.

How, sir, said I, can these things be? For both these things which you have spoken of are impossible. Even, said he, as these are impossible, so also are the earthly spirits without power and feeble.