Most modern search engines rank your site according to its content. The content that is most easily parsed is text. The frequency and relevancy of words dictate how it will rank against certain search terms. However, you should not let your church's theology and terminology get in the way of letting your site bubble to the top of the search pile.
Not About Theology
I know that theologies and terminologies are touchy subjects for some churches. Thus I will use an innocent example of a website for a dog walking service. You would obviously want to rank well for the search term "dog walking". Unfortunately, your business' name does not include the word "dog walking", but a clever reference like "Running Rovers" or "Fit Fidos". So how can you get your site to rank higher?
SEO and Repetition
The solution is not to simply mention the word "dog walking" as many times as possible in your content. For example: "We will always walk your dog with their dog walking collar and dog walking leash. This way your dog will always be safe while getting their dog walking exercise for the day." This is obviously very difficult to read. Also, search engine are getting smarter and can detect when text is over-stuffed with a particular word. However, changing terminologies and using synonyms might be a good solution for this.
Consider writing with not only dog, but with doggy, pup, puppy, canine, K-9, mutt, pooch, hound and man’s best friend. These are different ways to express generally the same thing. While pup and puppy might denote younger dogs, and K-9 makes you think of police dogs; they are still related to the generic term of dog. By using these other terms, you are not only making your content more conversational, but are adding a broader range of related search terms. Often times when you over-stuff content with keywords, it is marked as spam and your domain is penalized. Adding related keywords can generally be done without that risk.
Now that I have taken this nice wide arc, it is time to swing on back and show you how this ties to your church’s website. Despite what you call your church's summer youth program, it is most often associated with the keywords "vacation Bible school". You might also have youth programs with not-so-obvious names, such as my own church's "Blitz" and "Extreme". By also using the more generic terms of "youth programs", you not only rank higher for those more common terms, but you put it in context for your users to more easily understand.
Lastly, doing the opposite and taking things down to a more common level may be beneficial in certain areas. Do you practice pedobaptism or credobaptism (baptizing as a baby or an adult). Unless you are producing a white paper that debates the topic, the page titles and headers should be the more common term of "baptism". These higher profile area deserve the more generic term so your readership can more easily understand these complex topics.
When you write your content, see where you can add diversity. If you have an upcoming topic of sermon series, event, or even season (like Easter), be sure to write the content so that multiple synonymous terms are used to describe it. Are you stuck? Try Thesarus.com or HowRank.com’s Keyword Generator. Want to hear more? Get the straight scoop right from Google.