4:1 has ceased from sin. Some interpret this to refer to the character-building effects of suffering. But the preceding reference to baptism (3:21; cf. Rom. 6:1–10) indicates that Peter is thinking of the union of believers with Christ in His suffering and death, a union particularly symbolized by baptism (Rom. 6:4). Though Christ was always sinless (2:22; 2 Cor. 5:21; Heb. 4:15), He nevertheless fully identified with sinful humanity by coming “in the likeness of sinful flesh” (Rom. 8:3) and becoming subject to temptation, suffering, and death (Mark 1:12, 13; Heb. 2:10; 4:15). Christ “died to sin” (Rom. 6:10) in the sense that after His death and Resurrection He was no longer subject to the power of sin and death.