Some time ago I referred to Timothy Warren of DTS who used the analogy of guardrails for guarding the application of a message from straying off target. I’d like to use the same analogy with slight modification in respect to preaching a text.
The preacher builds a bridge between the Bible text in its world and the listeners in theirs. It may be helpful to imagine a guardrail either side of this road. One guardrail is the intended audience, the other is the purpose of the communication. On the Bible side of the bridge, the intended audience were the church or individual receiving the inspired text (i.e. the churches of Galatia). The purpose was specific in terms of Paul’s intent for those churches.
By the time the preacher gets over to today, he is also thinking of an intended audience (the congregation of Community Church this coming Sunday) and also has a purpose in preaching this text to them on this occasion.
Now if the audience this Sunday shares significant characteristics and cultural experiences with the original audience, then the guardrail comes straight across the bridge. And if the purpose for the sermon matches Paul’s purpose for his letter, then that guardrail also comes straight across.
But what if the audience is different (perhaps they haven’t gone after another gospel), and therefore the purpose is slightly different (encouragement with some warning, rather than open rebuke), then I imagine the guardrails shifting the road direction slightly (think of how your lanes are changed when there is construction on the motorway/freeway). The message of the text is not significantly changed (there are limits), but the sermon is adjusted from what the original did.
If this were applied to preaching a passage from Leviticus, then I imagine the considerable change in audience and purpose would be reflected in the less direct application of the text (a six-lane road narrowing to a two-lane road since we can’t apply it freely and directly), yet the road remains the same.
You cannot preach any truth from a particular passage. You can only preach the truth of that passage. However, the ease of transfer depends on the consistency of audience situation and sermonic purpose. Adjusting these guardrails will adjust the message (but the message must still be the message of the passage).