Question 174: What is required of them that receive the Sacrament of the Lord's Supper in the time of the administration of it? Answer: It is required of them that receive the sacrament of the Lord's Supper, that, during the time of the administration of it, with all holy reverence and attention they wait upon God in that ordinance, diligently observe the sacramental elements and actions, heedfully discern the Lord's body, and affectionately meditate on his death and sufferings, and thereby stir up themselves to a vigorous exercise of their graces; in judging themselves, and sorrowing for sin; in earnest hungering and thirsting after Christ, feeding on him by faith, receiving of his fullness, trusting in his merits, rejoicing in his love, giving thanks for his grace; in renewing of their covenant with God, and love to all the saints.
Question #173. Question: May any who profess the faith, and desire to come to the Lord's Supper, be kept from it? Answer: Such as are found to be ignorant or scandalous, notwithstanding their profession of the faith, and desire to come to the Lord's Supper, may and ought to be kept from that sacrament, by the power which Christ hath left in his church, until they receive instruction, and manifest their reformation.