How to show a page on our website with all entries / submissions made on a form?

I would like to add a guest book to our church website. Is it possible to have a page where all of the entries can be seen?

Yes, you can do that and there are several different ways to achieve that based on what you are after.

For example it would be possible to share a report page on your website as a guest book.

I believe that in that case the Grid Report or HTML report would be the best options. On the following links you can see more about each:

1. How to create a Grid Listing report?
2. How to create an HTML Table Listing Report?

Now you could also have a Google Spreadsheet shown on your website that would hold this data - if that is what you prefer - and set it all up so that the spreadsheet is embedded as not editable and integrate your jotform to it.

I would recommend reports over this approach, but if you wish you can set it up by following the steps here: How to Integrate Form with Google Spreadsheet

There is also a Submission View app that you could use that would allow you to have a different layout of the submissions - based on your own preferences.

There are some other options, but I presume that you are looking to have it displayed publicly to everyone - not to be password protected. If you wish that, do let us know and we would be happy to let you know about such options as well.