Calvin begins by studying the place that worship holds in the Christian faith, and he concludes that it is one of the two elements that define Christianity:
'If it be asked, then, by what things chiefly the Christian religion has a standing amongst us, and maintains its truth, it will be found that the following two not only occupy the principal place, but comprehend under them all the other parts, and consequently the whole substance of Christianity, viz., a knowledge first, of the right way to worship God; and secondly of the source from which salvation is to be sought. When these are kept out of view, though we may glory in the name of Christians, our profession is empty and vain.'
