1 Peter 3:13–17 contains a single thread of thought, making it difficult to subdivide. A possible division might be to see in 1 Peter 3:13–15a an internal focus (one's attitude in the face of suffering) and in 1 Peter 3:15b–1 Peter 3:16 an external focus (interacting with oppressors’ feedback). 1 Peter 3:17 is a wisdom saying undergirding the argument of the paragraph.
13 Now who is there to harm you if you are zealous for what is good?