It is important that the preaching text is a full and coherent unit from within the broader context. This requisite is similar to the first, in that it requires a careful examination of the text in order to properly discern the appropriate starting and ending point for any passage being studied. If a passage is inappropriately cut into smaller sections, the intent of the broader passage may be distorted or lost. However, misidentifying the appropriate boundaries to a preaching text is different from prooftexting because smaller passages may still compose a full thought, even if they do not compose a full preaching text.
For example, Mark 4:10-12 contains a full thought. In these verses Jesus affirms that the secret of the kingdom of God has been given to His disciples but that for those outside the secret is communicated in parables, thus fulfilling Isaiah 6:9-10. Therefore, it is possible to choose these three verses as a preaching text without falling into prooftexting. However, these three verses do not compose a full and coherent unit. The full passage stretches from Mark 4:1-20.
Unless all twenty verses are selected as a single preaching text, the conclusions of the sermon may miss the intent of any given verse or group of verses within. The reason for this is the intentional structure of the passage. The first nine verses provide the parable of the Sower, who sows seed on the path, on rocky ground, among the thorns, and in good soil. Verses thirteen through twenty provide Jesus’ interpretation of the parable. Stuck in the middle is this pithy passage about Jesus’ reason for teaching in parables. If any of the three smaller sections are isolated from the broader passage, then the deep meaning of the passage becomes obscured. Each shorter section is co-dependant on the other two. It may be tempting to preach Mark 4:1-9and 4:13-20. However, if this is done then the preacher will almost assuredly miss the point of the passage.
The easiest conclusion to a preaching text that includes only Mark 4:1-9, 13-20 is that good soil bears fruit. The emphasis will be on the soil and the harvest that results. It is a very short leap from this point to the exhortation, “Therefore people, be good soil.” Preachers then can wax eloquently about the dangers of being a person of the path, or of the rocks, or among the thorns. The result will be a highly motivational moralistic interpretation that focuses almost exclusively on the soil. That is, on us, the people listening to the parable.
If we insert Mark 4:10-12, however, the focus shifts away from the soil and rightly illuminates the Sower. These three verses show us that the deeper meaning of the passage actually has to do with the Sower, not with the soil. The question posed by this full passage is this: “Why, Jesus, do you teach in parables?” The answer: “So that only the good soil receives the Word, understands it, and produces a harvest.” The passage is not an appeal to people, that they become good soil. Rather, the passage is an explanation for why Jesus is meeting resistance in His ministry. “People are rejecting me,” says Jesus, “Not because my ministry is failing or because I am doing something wrong, but because those who reject me are not good soil. However, I came to preach the Word of truth indiscriminately to all, even to those who will not and cannot receive it, that I might bring Isaiah’s prophesy to its proper fulfillment.”
Therefore, as this example illustrates, Mark 4:1-9, 13-20 depends on Mark 4:10-12. The inverse is also true, Mark 4:10-12 does not make full sense without the flanking material. The full and coherent preaching text for these verses, therefore, necessarily requires Mark 4:1-20 and Isaiah 6:9-10, though the preacher may decide to include all of Isaiah 6:8-13.
In summary, the preacher must be careful not to prooftext, which he can successfully avoid by selecting a text that contains a complete thought. And, even passages with a complete thought must be carefully selected to ensure that the preaching text is a full and coherent unit. Negligence in any one of these areas might cause the conclusions of the sermon to misrepresent the actual intent and meaning of the divinely inspired Word of God.