If you want a WordPress website, you have 2 options: Managed or Self Hosted.
Some churches use WordPress.com, which is a free managed service.
A managed site takes care of all the technical aspects of the site, including hosting and updates.
However WordPress.com has restrictions that are not ideal for church based sites, and their paid for add-ons are not the cheapest!
A more professional option is to use Self-hosted WordPress but the drawback is you have to obtain hosting and get someone to install and set it up for you. You then need to ensure it is regularly updated and maintained.
UK Churches.org offers the best of both worlds. – We manage the site for you, but you get a much wider range of plugins and addons, and a church-centred approach that understands what you are trying to achieve and works with you to accomplish your goals.