Catholics and Lutherans signed the Joint Declaration on Justification in 1999. This ecumenical agreement claims to resolve all church-dividing differences on justification without requiring doctrinal revision, a claim that Engrafted into Christ challenges with a twofold thesis. First, the historic disagreement over justification was substantial; thus, doctrinal revision is a sine qua non condition of rapprochement. Second, portions of the Declaration appear irreconcilable with Catholicism. A concluding series of original reflections illustrates the intelligibility of Catholic teaching, identifies a self-destructive element in sola fide, and challenges structural elements of Lutheran theology. Experts as well as educated laypersons will be interested in this book.