True or False -- Doctrinal Assertions

An assertion must be true or else it is false. If is true, it is always true. If an assertion is considered true some times and false at other times, then it is no longer an asertion.

Assertions are fundamental to Christian doctrine (such as, God created the heavens and the earth; Jesus was born of a virgin; Jesus rose from the dead; etc.). An example of a doctrinal assertion from the Lutheran Confessions is the Law always accuses (lex semper accusat). The phrase the Law always accuses is used nearly ten times in the Book of Concord (and only in the Apology to the Augsburg Confession).

While the phrase the Law always accuses is a doctrinal assertion, some people say that the law accuses only according to its second use (function), but not according to its first or third. With this exception, the statement the Law always accuses is no longer true. On several occasions, I have asked where this distinction comes from. However, no one has provided substantive documentation. So I remain at a loss as to the origin and necessity of this distinction.

If someone says "the law always accuses, except...," then he in essence denies the doctrinal assertion that the law always accuses. This is very confusing.