Tim, DEVONthink doesn’t force one into a template format for documents. Just import your sermons and notes into the database.
You can organize related documents into groups. Once your database has grown sufficiently, the Classify button can suggest a group location for a new document. Using replicants or duplicates you can organize a document into multiple groups, if that’s useful. Organization is entirely up to you, whatever you find useful.
You can create networks of relationships using Wiki links or hyperlinks. Clicking on such a link will open the referenced document. For example, if a sermon refers to a verse in the Bible, and that verse already exists as a document, you can link from the sermon to the verse by selecting an appropriate word on phrase in the sermon, then Control-click (right click) and choose the contextual menu option Link To, then choose the verse document.
You can add searchable plain text in the Comment field of a document’s Info panel. You can enter notes or keyword tags in this way. Or you can "tag’ items with a Label color (Data > Label - Color). Note that in the Search window you can search just the Comment field or a specific Label color, for example.
Option-click on a word, e.g., Samuel, and a drawer will pop out listing all the documents in the database that contain that word. Or select a word or phrase and press Command-/ (Lookup); a search window will open with that word or phrase already entered.
While viewing a document, click on the See Also button. A drawer will pop out with a list of other document that the artificial intelligence feature has found to be contextually related. Some of those suggestions may be useful, others not. You are the decision maker, but this can be a useful way to interact with the information content in your database.
DEVONthink provides a rich environment for storing and organizing your information and for writing and research. Perhaps you might start your organization with two major groups, e.g., Old Testament and New Testament. Under each you might then have subgroups by document type (e.g., sermons, commentaries, quotations, etc.) – whatever fits your needs and preferences. Think of your groups as holding clusters of related information, defined more tightly by subgroups and subgroups within subgroups. But some features such as Search and See Also are not dependent on your organizational structure at all.
Suggestion: Start by importing content into your database and begin experimenting with what you can do. Try some searches (Tools > Search) and experiment with different configurations of the query setups in the left column of the search window.
There are a great many commands available in DEVONthink. Many of them are available only within a given context. I’ve been using DEVONthink for years and am still learning new tricks. My advice is not to start by trying to memorize all the possible commands, but to dive in and learn by doing.