The Heidelberg Catechism (1563), one of the Three Forms of Unity, is a Protestant confessional document taking the form of a series of questions and answers, for use in teaching Reformed Christian doctrine. It was written in 1563 in Heidelberg, present-day Germany. Its original title translates to Catechism, or Christian Instruction, according to the Usages of the Churches and Schools of the Electoral Palatinate. Commissioned by the prince-elector of the Electoral Palatinate, it is sometimes referred to as the "Palatinate Catechism." It has been translated into many languages and is regarded as one of the most influential of the Reformed catechisms.
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