The touchstone for evalutating church-state relations under the Establishment Clause of The Bill of Rights is the test enunciated by the Supreme Court of the United States in "Lemon v. Kurtzman," in 1971, otherwise known as "The Lemon Test".

There the Court identified three distinct criteria for determining the constitutionality of legislation under the Establishment Clause of the Bill of Rights.

First: the statute must have a secular legislative purpose;

Second: its principal or primary effect must be one that neither
advances nor inhibits religion;

Third: the statute must not foster "an excessive government entanglement with religion."

Failure of a statute to satisfy any one of these criteria requires its invalidation.