Website builders usually offer ad-enabled free tiers to attract customers. This is a sensitive issue because most ads are not appropriate for a church website. I recommend Weebly here because their free plan only advertises Weebly itself, so no third party advertisers means you know what your visitors will see, which is pretty innocuous up-sells for their premium plans.
If you're on the lookout for a standard site but your congregation can't afford to pay too much (or anything), Weebly gives you just that: a basic online presence that you can count on. And when you're ready you can easily upgrade to use your own domain ($4 per month), or tap into their more advanced features like membership areas, online store (for donations), password protection and unlimited storage.
You won't get the flashy templates the other church-focused builders on the list offer, or the free content population for your website, but the support is good and the websites are stable and secure, so give them a try for free.