2 Peter 3:17 - Matthew Poole's English Annotations on the Holy Bible

Seeing ye know these things, which I have been now writing to you of, viz. That the Judge will certainly come; or, that heretics, deceivers, and scoffers will come; or both may be comprehended. Beware lest ye also; as well as others have been. Fall from your own stedfastness; the stedfastness of your faith. This admonition he gives them, not to discourage them with fear of apostacy, but to awaken them to that holy care which would be a means to prevent it; and so to keep them from security, and trust in themselves, not to weaken their faith, and reliance on the promise.