In this month's edition of Tabletalk, Michael Horton examines the orgin and true meaning of this misunderstood and misused motto. Here's a snippet:
This perspective keeps us from making tradition infallible but equally from imbibing the radical Protestant obsession with starting from scratch in every generation. When God’s Word is the source of our life, our ultimate loyalty is not to the past as such or to the present and the future, but to “that Word above all earthly pow’rs,” to borrow from Luther’s famous hymn. Neither behind us nor ahead of us, but above us, reigns our sovereign Lord over His body in all times and places. When we invoke the whole phrase — “the church Reformed and always being reformed according to the Word of God” — we confess that we belong to the church and not simply to ourselves and that this church is always created and renewed by the Word of God rather than by the spirit of the age.The article is quite helpful so check it out here.