God's Holy Fire - Part 2

Okay, I'm trying to like God's Holy Fire: The Nature and Function of Scripture but it isn't working out too well.  I got to page 64 where I found this:

We can learn at times from how others - Jews and Christians throughout the history of the church - have understood these texts.  In so doing, we will learn that our own perspectives on the texts do not exhaust their possible meanings.  For example, we may read Isaiah 53 in the light of Jesus' last week, as Christians usually have, or we may also appreciate Jewish readings of this text that understand the "suffering servant" to be Israel itself.  Both readings have value, and there is no reason to insist that one and only one of them can be true.  Truth can only come from consideration, over time, of many factors.  It comes by reading the many texts of Scripture again and again and never allowing any one of them to silence the others.

I'm trying to decide if this paragraph is a sort of biblical relativism or if the concept is that we can eventually arrive at truth if we study hard enough.  When the author writes: "Both readings have value, and there is no reason to insist that one and only one of them can be true" that sounds like a denial of the existence of absolute truth, but then the next sentence seems to "redeem" the passage a little bit by indicating that reading "again and again" will eventually lead to "truth" since it comes from a "consideration of many factors."  Clearly if you are a Christian and believe in the New Testament then you have to believe that Isaiah 53 is talking about Christ since the New Testament writers quote it in such a way:

Who has believed what they heard from us? And to whom has the arm of the LORD been revealed?
(Isa 53:1)

Though he had done so many signs before them, they still did not believe in him, so that the word spoken by the prophet Isaiah might be fulfilled: "Lord, who has believed what he heard from us, and to whom has the arm of the Lord been revealed?"
(Joh 12:37-38)

Surely he has borne our griefs and carried our sorrows; yet we esteemed him stricken, smitten by God, and afflicted.
(Isa 53:4)

That evening they brought to him many who were oppressed by demons, and he cast out the spirits with a word and healed all who were sick. This was to fulfill what was spoken by the prophet Isaiah: "He took our illnesses and bore our diseases."
(Mat 8:16-17)

Of course the clincher in this regard is when Philip finds the Ethiopian eunuch reading from Isaiah (Acts 8:28) and the passage that the Ethiopian eunuch is reading says this:

"Like a sheep he was led to the slaughter and like a lamb before its shearer is silent, so he opens not his mouth. In his humiliation justice was denied him. Who can describe his generation? For his life is taken away from the earth."
(Act 8:32-33)

Naturally Isaiah 53:7-8 is the passage he was reading:

He was oppressed, and he was afflicted, yet he opened not his mouth; like a lamb that is led to the slaughter, and like a sheep that before its shearers is silent, so he opened not his mouth. By oppression and judgment he was taken away; and as for his generation, who considered that he was cut off out of the land of the living, stricken for the transgression of my people?
(Isa 53:7-8)

So the eunuch asks (Acts 8:34):

"About whom, I ask you, does the prophet say this, about himself or about someone else?"

And does Philip say, "Well, we aren't really sure.  Some Jewish scholars believe that the prophet is talking about Israel, which is an interpretation that certainly has value, but I think another, equally valid, interpretation is that it might be this Jesus fellow.  But I could be wrong."  Of course not!  Acts 8:35 says:

Then Philip opened his mouth, and beginning with this Scripture he told him the good news about Jesus.

So when the good writers of God's Holy Fire: The Nature and Function of Scripture write that, "For example, we may read Isaiah 53 in the light of Jesus' last week, as Christians usually have..." I have to feel like they are being misleading to the reader not to state it like so: "For example, we may read Isaiah 53 in the light of Jesus' last week, as Christians always have..." or better yet, "For example, we may read Isaiah 53 in the light of Jesus' last week, as the New Testament writers did..."

The question in my mind is whether this is due to malice or ignorance.  Do the writers of this book really know so little of the Bible they are supposedly writing about or are they purposely trying to lead people astray?