1 Peter 4:1

4:1 So, since Christ suffered ¹  in the flesh, you also arm yourselves with the same attitude, because the one who has suffered in the flesh has finished with sin, ² 

1 Peter 2:9

2:9 But you are a chosen race, a royal priesthood, a holy nation, a people of his own, so that you may proclaim the virtues ³  of the one who called you out of darkness into his marvelous light.

[4:1]  ¹ tc Most mss (א² A P Ï) add ὑπὲρ ἡμῶν (Juper Jhmwn, “for us”); others (א* 69 1505 pc) add ὑπὲρ ὑμῶν (Juper Jumwn, “for you”), the first hand of א also has ἀποθανόντος (apoqanonto", “since he died”) instead of παθόντος (paqonto", “since he suffered”). But the reading without ὑπὲρ ἡ/ὑμῶν best explains the rise of the other readings, for not only is there confusion as to which pronoun belongs here, but the longer readings, being clarifications, are evidently motivated readings. The shortest reading is found in important and early Alexandrian and Western witnesses (Ì⁷² B C Ψ 0285 323 1739) and is strongly preferred.

[4:1]  ² sn Has finished with sin. The last sentence in v. 1 may refer to Christ as the one who suffered in the flesh (cf. 2:21, 23; 3:18; 4:1a) and the latter part would then mean, “he has finished dealing with sin.” But it is more likely that it refers to the Christian who suffers unjustly (cf. 2:19-20; 3:14, 17). This shows that he has made a break with sin as vs. 2 describes.

[2:9]  ³ sn This verse contains various allusions and quotations from Exod 19:5-6; 23:22 (LXX); Isa 43:20-21; and Mal 3:17.