We've done a lot of work tagging songs with themes but sometimes we might use a different but related term for what you searched for. For example, if you searched for "Eucharist", in the past you might be disappointed with the results because most song related to the Lord's Supper are instead tagged with "Holy Communion". But the site now looks for related themes to your search and displays them just under the search bar. You can then click on any of them to search on the suggested wording instead.
Try searching for Holy Ghost.