Why Preach from the Bible?

Adult Sunday School this week: Expository Bible preaching (and hearing) as a part of what it means to let Jesus Christ determine the ministry of the church.

Found this on wikipedia:
Expository preaching (also referred to as systematic exposition) is a form of preaching that expounds upon the meaning of a particular text or passage of Scripture. While the term could be used in connection with any religion that has organised worship that includes scriptural teaching, the term is most usually used in relation to Christianity, and is thus concerned with the exposition of the Bible. The practice probably originated from the Jewish tradition of the rabbi giving a "Dvar Torah", explaining a passage from the Torah, at the conclusion of prayer services.

Expository preaching differs from topical preaching in that the former concentrates on a specific text and discusses topics covered therein, whereas the latter concentrates on a specific topic and references texts covering the topic.