Analysis of the Shorter Catechism Definition The Shorter Catechism begins by employing the phrase “a spirit” to describe God—he is “a spirit.” This phrase is then qualified by three adjectives—“infinite, eternal, and unchangeable.” A prepositional phrase introduced by “in” then modifies the three adjectives; its seven nouns are in turn each qualified by the three adjectives. What this representation intends to show is this: that God is a personal (see the “his”), noncorporeal Being who is infinite,