If you are using free version of Sermon Manager plugin in Genesis Framework, you will notice that you will still have 'Primary Sidebar' even after using Fullwidth option in your Genesis theme customizer.

To hide 'Primary Sidebar' inset below CSS in your style.css file...

.tax-wpfc_preacher .sidebar,
.tax-wpfc_bible_book .sidebar,
.tax-wpfc_service_type .sidebar,
.single-wpfc_sermon .sidebar,
.post-type-archive-wpfc_sermon .sidebar {
	display: none;
}