Archaeology is the study of the material remains left behind by cultures of the past. For this reason it is, and should be, pursued with as much scientific discipline as can be mustered in order to "unearth" the most reliable data. However, when it comes to archaeological finds that relate to the biblical world, and particularly events and places mentioned in the text, the science of it can become quite obscured, leaving a pseudo-science resembling a slightly more intellectual yet very religious exercise. This is further complicated when determining what use is the data to the pastoral function of preaching. Can the pulpit and the spade become friends, or are they uncomfortable acquaintances that are not sure what to do with one another?
I believe the answer begins with determining what one thinks archaeology related to the biblical world ought to be used for. Among the various schools of thought there are two which receive the most press due to remaining the most vocal: (1) Prove the Bible is true by setting out to find ancient sights, artifacts and inscriptions that validate its historical claims, and (2) assume the Bible is not true until archaeological finds support its claims.
Both approaches have considerable problems. The 1st approach assumes that the Bible is always conducting straight historical reporting (often in violation of their own hermeneutic principles of accounting for literary genre, idiom, parable, figures of speech, etc.), and therefore will force the scientific data to fit their presupposed interpretation of the Bible by any means possible. In addition, in their zeal to "prove the Bible," the 1st approach will often bypass much of the scientific process and declare an interpretation proved with sketchy or incomplete data that is later disproved. This gives ammunition to those who desire to disprove the Bible.
The problem with the 2nd approach is that it begins from a perspective of disbelief. It is expected that only provable claims must be believed. This is not only in contradiction to the principle of faith preceding understanding, it also denies the reality of the great limits on archaeology's ability to prove anything. So little of what can be discovered, identified, excavated and analyzed has actually been done as to leave those supposedly objectively disbelieving to appear zealously so. One could just as well assert that, upon discovering a toe nail in a graveyard, a full human body never existed here because we have not found the rest of it. Rubbish!
What does this say for the Bible expositor? I for one seek a third approach. This approach is shared among critical evangelical scholars, committed to asserting the inerrancy of Scripture in all that it affirms. This approach suggests that the Scriptures are inerrant, but my interpretation may very need amendment as data illuminates my understanding of it. I do not expect that archaeology will "prove the Bible" because I am becoming increasingly more aware of the limits of archaeology. However, I do understand that archaeology (when itself is interpreted well) can aid in my interpretation of the Scriptures. I in turn seek to interpret the Scriptures so as to discover the transcendent truth expressed in its life-giving pages. That same truth is what must come from the pulpit.
I am persuaded that archaeology is a tool that is vital to the expositor's task of helping his people enter the biblical world. In this way they can better relate to the people to whom the truth expressed in the text first came. In addition, the truth from the text is better illuminated for purposes of application in the present time. The pastor ought to strive to connect the people of those times with those in his congregation now. In addition to the commentaries on the text, let him also read published (and scholarly credible) works on the lifestyle, culture and practices of the times that his passage is set in. Let him know something of Egypt when he speaks of Moses. Let him know something of Ugarit when he speaks of Baal. Let him know something of Babylon when he preaches from Daniel; Palestine and the Gospels; Anatolia and Ephesus; Greece and Corinthians; Rome and Revelation. Indeed the pulpit and the spade are great companions, and pastors must strive to be comfortable with both.