Good Questions...
Most evangelicals believe that if a passage of the Bible seems
unclear in its meaning, it should be interpreted in the light of Scripture "as
a whole". But what does "Scripture as a whole" mean? In practice, if
not theory, it means the working systematic theology of the interpreter, or of his
own theological tradition. An evangelical... would not hold to that tradition
unless he believed that it did represent the wholeness of the biblical witness.
Nevertheless, if this state of affairs has been correctly described, he is now in a
serious difficulty. For if the Bible must always accord with a theology that has already
been accepted, how can the truth of a biblical passage ever confront him afresh with an
unfavorable judgment?
... Tony Thiselton, "Understanding God's Word Today"