"Lemon" Test — this three-part test is commonly used to determine whether a government's treatment of a religious institution constitutes "establishment of a religion" (which is prohibited under the establishment clause of the First Amendment). Under the "Lemon test," named after the Lemon v. Kurtzman, 403 U.S. 602, 91 S. Ct. 2105 (1971), case, a government can only assist a religion if (1) the primary purpose of the assistance is secular; (2) the assistance does not promote or inhibit religion; and (3) there is no "excessive entanglement" between church and state.