Most churches and ministries believe everything they do is part of their overall mission to further the work of Christ. Therefore, there couldn't possibly be anything unrelated about their operations...or could there?
Many organizations operate book or music stores, concession stands, coffee shops, or teen game rooms. They may sell advertising spots in a magazine or rent space in their building. So they may, unknowingly, have unrelated business income subject to tax.
Let's look at how to determine if your organization has an issue.