There are two possibilities. The reference could be to the words Peter just wrote so that the meaning is, You were called to bless those who do evil to you or revile you (Matthew 5:43–44). The reference could also be to the words Peter intends to write next so that the meaning is, You are called to bless those who do evil to you so that in turn you may be blessed (Matthew 5:11–12). Grammatically the reference can go either way. Similarly, biblical doctrine permits either approach. Yet following Peter’s line of thought the obvious reading is the former, that is, Peter tells his readers to bless their oppressors because that is what they are called to do. Peter’s readers have been born again so that they have an eternal inheritance, an inheritance they would wish on everyone else too, including persecutors (1 Peter 2:12; 1 Peter 3:1). In fact, Jesus himself set the example when he blessed (= prayed for) his oppressors (Luke 23:34).
9 Do not repay evil for evil or reviling for reviling, but on the contrary, bless, for to this you were called, that you may obtain a blessing.