According to concealedcarry.com, there are two states that ban concealed carry in churches, Nebraska and Louisiana. Nebraska allows a church to authorize an armed security team if the team members have carry permits and if written notice is given to church members. Louisiana law is similar but requires an extra eight hours of training every year. Seven states and D.C. that require the permission of a church leader to conceal carry firearms in church, and 41 states where carry in churches is treated the same as any other private property.
Of the 41 states that treat churches the same as other private property, eight are “may issue” states, where the permit-issuing authority can deny the exercise of the Second Amendment for almost any reason. Those states are California, Delaware, Hawaii, Massachusetts, Maryland, New Jersey, New York, and Rhode Island. Within these states, the issuance of permits ranges from almost none in Hawaii and New Jersey, to fairly large numbers, as in upstate New York and Massachusetts.
There are 13 states that do not require a permit to carry concealed. They are Alaska, Arizona, Arkansas, Idaho, Kansas, Maine, Mississippi, Missouri, New Hampshire, North Dakota, Vermont, Wyoming, and West Virginia.