Second Peter focuses on two of Christianity’s basic challenges: is the gospel message reliable and is it unchangeable? Peter provides evidence for its trustworthiness, and warns against trying to change it to make it more palatable to worldly tastes. But he doesn’t end it there. A trustworthy message is valueless if it makes no impact on the lives of the hearers. One cannot do what one doesn’t know to do. But knowing, and not being obedient, is the same as ignorance – and God will judge both. There is no excuse for a Christian now knowing the will of God. And even less for not being obedient.