The [Westminster] Confession teaches that by their inspiration the Scripture are made not only to contain but to be the Word of God. In i.2 the alternate name of Holy Scripture is "the Word of God written." In i.4 it is declared that Holy Scripture "is the Word of God"; in i. 5 it is pointed out how it evidences itself "to be the Word of God." This phraseology pervades the whole document (cf. iii. 13; x. 1, 4; xiii. 1; xiv. 1, 2; xvi. 1; xx. 2; xxi. 5, 6, 7; xxii. 7, xxiv. 4; xxx. 2; Shorter Catechism, Q. 2, 99; Larger Catechism, Q. 3, 4, 67, 156, 157, 158, 159, 160 etc.). The Holy Scripture which is thus declared to be the Word of God is defined to be itself "all the books of the Old and New Testament"; and cannot, therefore, be thought to be only selected passages in those books. It is called the "Word of God written" to distinguish it by its accidents from the spoken Word of God, as given to the prophets aforetime, in the sense of i. 1, and as explained in the citation from Calamy. Finally, when we read in the Shorter Catechism of "the Word of God, which is contained in the Scriptures of the Old and New Testaments," we are not reading of a distinction within the limits of Scripture between a word of God and a word not of God, as if it were only asserted that the former is to be found indeed within the Scriptures; but we are reading an anti-Romish and anti-Mystic declaration that the only Word of God that is recognized is that contained in the Scriptures. This, everyone acquainted with the literature of the times will perceive at once; ... As simple historical students, we must admit that the Westminster Confession is committed to the position that the Bible not only contains but is the Word of God. [B.B. Warfield, "The Westminster Doctrine of Inspiration," in Selected Shorter Writings, 2:576-7]
Anyone who believes in any version of "limited inerrancy" or flat our deny inerrancy, and/ or who take the Barthian view of Scripture, cannot hold to the Westminster Confession concerning this issue and thus they cannot subscribe sincerely and truly to that Confession.