One of the themes of 2 Peter is that he is writing against people who are “following their own sinful desires” (3:3). The contrary is what Peter sees as ideal.
The Christian life is in many ways a way which we do not follow the desires within us that are sinful, but we are wanting to be transformed and to change our ways.
We find out what is sinful as we read and obey God’s word, but I am reminded that the miracle of following Jesus is not just that we are embracing new and living ways, but God transforms our desires in the process.
Christianity is not us gutting it out and trying to live an impossibly righteous life. It is true that God wants us to live the way which gives life. But in order for us to live that way, we need our hearts changed.
Paul and Peter seem to be on to something–that resisting our sinful desires is a process that God wants us to go through. And the miracle of the Christian life is that he will do it for us as he renews us in his image.