Americans gave more than $30 billion dollars in bequests made through wills and estate plans in 2016, according to the latest Giving USA report. But few churches talk to their members about how they can make such gifts to their churches after they die. For example, a 2013 study of Southern Baptist pastors found that 86 percent provided no information to church members about estate planning.

"Many pastors are apprehensive even when speaking about tithing," says John Kea, executive vice president and general counsel for the Nashville-based Southern Baptist Foundation. "Few know where to start when talking about estate planning."

And few churches have the infrastructure in place to help church members who want to make a bequest, Kea said.

Yet many church members may be open to remember a church in their estate, said Steve Allison, a financial services representative for Covenant Trust Company—a financial management and legacy planning resource to individuals, charitable organizations, and ministries, both inside and outside the Evangelical Covenant Church. Through workshops Allison gives to church groups on estate planning, he reminds churchgoers that they have often benefited from Christians who came before them.