Since faith, then, is in our power, inasmuch as every one believes when he likes, and, when he believes, believes voluntarily; our next inquiry, which we must conduct with care, is, What faith it is which the apostle commends with so much earnestness? For indiscriminate faith is not good. Accordingly we find this caution: “Brethren, believe not every spirit, but try the spirits whether they are of God.” Nor must the clause in commendation of love, that it “believeth all things,” be so understood as if we should detract from the love of any one, if he refuses to believe at once what he hears. For the same love admonishes us that we ought not readily to believe anything evil about a brother; and when anything of the kind is said of him, does it not judge it to be more suitable to its character not to believe? Lastly, the same love, “which believeth all things,” does not believe every spirit. Accordingly, charity believes all things no doubt, but it believes in God. Observe, it is not said, Believes in all things. It cannot therefore be doubted that the faith which is commended by the apostle is the faith whereby we believe in God.
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 1, vol. 5 (Schaff, 1887), public domain (Public domain).