This article considers the phrase "justification by faith," with special emphasis on the word "alone." The study starts with a historical perspective, noting the great controversy that the word stirred up between the Roman Catholic and the Reformers. Those who contended against the use of that small word state that the word  does not specifically occur with justification in Scripture, and therefore its use amounts to an addition to Scripture. Those who are for the word appeal to the total meaning gathered in all the contexts in which justification is the subject. Further, the author argues for the relevance and centrality of this sola fide principle in today’s believing community.