The idea of being diligent was already mentioned by Peter earlier in his letter (2 Peter 1:5, 2 Peter 1:10). In this context it has to do with the pursuit of moral purity in order to make one’s calling and election sure.1 The appropriate lifestyle of a follower of Christ is not automatic, it requires energy and effort. Diligence (effort) is required for pursuing the godly virtues necessary for eternal life (2 Peter 1:5–11); it is also necessary for enjoying the new heavens and earth (2 Peter 3:14).2
14 Therefore, beloved, since you are waiting for these, be diligent to be found by him without spot or blemish, and at peace.