This chapter sifts through the various contemporary interpretations of the Pauline phrase “in Christ.” Based on the likely origin of the phrase and the way it functions in Paul’s argument, it is suggested that for Paul, union with Christ expresses genealogy and lineage. By being “in Christ” one is folded into Abraham’s family. An analysis of multiple Pauline letters suggests that the means of being united with Christ is baptism. This interpretation calls for a revision of traditional Protestant accounts of the ordo salutis, in particular of the tendency to separate baptism and union in Christ.