The Westminster Larger Catechism (1648)

The sacraments of baptism and the Lord’ s supper differ, in that baptism is to be administered but once, with water, to be a sign and seal of our regeneration and ingrafting into Christ,¹ and that even to infants;² whereas the Lord’ s supper is to be administered often, in the elements of bread and wine, to represent and exhibit Christ as spiritual nourishment to the soul,³ and to confirm our continuance and growth in him,⁴ and that only to such as are of years and ability to examine themselves.⁵