Here "We who died to sin" refers to those who follow Jesus, who are now like dead people who cannot be affected by sin. Paul uses this rhetorical question to add emphasis. Alternate translation: "We are now like dead people on whom sin has no effect! So we certainly should not keep on sinning!" (See: [[rc://en/ta/man/jit/figs-metaphor]] and [[rc://en/ta/man/jit/figs-rquestion]])