John Calvin Commentary 1 John 2:26

"These things have I written unto you concerning them that would lead you astray." — 1 John 2:26 (ASV)

These things have I written unto you. The apostle excuses himself again for having admonished those who were well endowed with knowledge and judgment. But he did this so that they might seek the guidance of the Spirit, so that his admonition would not be in vain; as though he had said, “I indeed do my part, but it is still necessary that the Spirit of God direct you in all things; for I will beat your ears, or rather the air, in vain with the sound of my voice, unless He speaks within you.”

When we hear that he wrote concerning deceivers, we should always remember that it is the duty of a good and diligent pastor not only to gather a flock but also to drive away wolves; for what good will it do to proclaim the pure gospel if we overlook the deceptions of Satan? No one, then, can faithfully teach the Church unless he is diligent in banishing errors whenever he finds them spread by deceivers. What he says of the unction having been received from him, I refer to Christ.