There are many types of literature present in the Bible, which is a compendium of sixty-six different books by many different authors written over the span of centuries. Within the Bible, styles of literary expression are quite varied and unique in many ways. There are the historical books, such as Genesis, Exodus and Deuteronomy in the Old Testament and the Gospels and the book of Acts in the New Testament; visionary literature in Daniel and Revelations; and the poetical literature of the Song of Solomon and the Psalms. Doing a comparative or detailed study of the various literary styles of the testaments can provide you with a wealth of academic material that will make a quality literary thesis. Highlight a particular genre, then compare and contrast it with the similar books within the same testament.
If you lean towards the study of the Old Testament, consider writing a thesis on the intricacies of the Hebrew laws that are dictated within the second, third, fourth and fifth books of the Old Testament. You can narrow your focus on the functions within the Tabernacle, the elements of the priesthood, the regulations regarding daily life, relational prohibitions, or any other aspect of Hebrew law in which you are particularly drawn. As with any focus on Old Testament theology, you will need to specialize in Hebrew as your language of choice within your theological coursework. Thesis of this nature often call for a detailed explanation and understanding of the original Hebrew within the context of your focus.
When you are choosing your area of specialty in Divinity school, you will be asked whether you choose to study Hebrew or Greek -- Hebrew for the Old Testament, and Greek for the New Testament. Following your language coursework's natural arc, you can choose to explore the influences of Greek life, writing, and language on the First Century church and everyday life in Judea during the time of Jesus and the Apostles. This area of coursework will include an average of two years worth of study in Ancient Greek and will provide you with a deep understanding of the wording of the New Testament language.
Consider writing your thesis on the Epistles of the New Testament. This area of coursework will require you to declare a major within the confines of the New Testament, but will provide you with ample material with which to explore your understanding of the Epistles. You can focus on the Epistles of one particular author, such as Peter, Paul or John. A comparison of the literary styles of the Epistles can also provide you with an interesting literary thesis. You will be required to have a considerable proficiency in Ancient Greek to make your thesis and will have to provide an in-depth exegesis on passages of Greek contained within the Epistle you wish to study.