--All Christian traditions say that.
--To gain credibility this claim would need to be made with at least Roman Catholic and Orthodox theologians in the room.
--This triumphalist claim is consistent with evangelicalism’s polemical roots and history.
--The claim marginalizes, if not ignores, the tremendous theological diversity in historic Christianity as well as in the church today (synchronic and diachronic diversity).
--The claim assumes that this diversity is a problem with God.
--Related to 4 and 5, the claim assumes something of the Bible, namely that it presents one detailed yet coherent spiritual narrative that can be teased out, systematized, and defended.
--Not all evangelicals are comfortable with this rhetoric.
In the rest of the post he offers "a defense of the evangelical narrative."
Have at it...