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Here is today’s entry:
Latin “faith alone”
The historic Protestant doctrine that the only instrumental cause of justification, from the human perspective, is faith. While God is the ultimate cause of justification, Protestants believe that faith in Christ through the message of the Gospel is necessary. There are no works, no matter how meritorious they may seem, that can add to justification (Eph. 2:8-9). This doctrine, according to Protestants, finds its roots in the teachings of Paul but was obscured in the middle ages and restored during the Reformation. Many Protestants would be quick to point out that it is not the doctrine itself that saves, but the reality that the doctrine represents. In other words, one is saved by faith alone, not by belief in the doctrine of faith alone. As well, most Protestants would say that “it is faith alone that saves, but the faith that saves will not be alone.” This doctrine represents a major point of distinction between Protestants and Catholics, Mormons, Jehovah’s Witnesses, and, often, Eastern Orthodox.
For more on this, see Michael Horton’s article “Are We Justified By Faith Alone? – What Still Divides Us: A Protestant & Roman Catholic Debate.”
Also, for a historical look at the doctrine of Justification, see Oden’s A Justification Reader.