J.G. Vos wrote a series of studies of the Larger Catechism that first appeared in Blue Banner Faith and Life (1946-49) and has never circulated widely. G.I. Williamson has edited Vos's commentary, and P&R is publishing it in book form for the first time. Because the Larger Catechism supplements the Shorter Catechism on such topics as the church and the means of grace, Presbyterians dare not ignore it. This edition of J.G. Vos's commentary will encourage a recommitment to the Larger Catechism's increased use and study.