How often this Sacrament was to be observed was left to the judgment of individual congregations, but frequent celebration was recommended. Calvin thought it proper that the Lord's Supper should be celebrated monthly, but finding the people opposed to such frequent celebration he considered it unwise to insist upon his own views. With his opinions on this matter, those of Knox were quite in harmony. The Sacrament of Baptism was likewise characterized in its administration by similar simplicity, and yet it is evident that, in this more than in any other part of public worship, the minister was restricted to the forms provided both in prayer and in address. The rubrics which govern the two prayers of the service and the address to the parents, make no mention of alternate or similar forms being permitted. In this the Book of Common Order differs from the Book of Geneva, which allowed the minister liberty in these parts of the service. There would seem, therefore, to be an evident intention on the part of the Scottish reformers in thus departing from their custom in other parts of worship. It may be that inasmuch as Baptism is the Sacrament of admission into the Church, it was deemed advisable that for the instruction of those seeking membership therein, either for themselves or for their children, the form of sound doctrine set forth at such a time should not be varied even in the manner of statement. The Sacrament was administered in the Church "on the day appointed to Common Prayer and preaching," instruction being given that the child should there be accompanied by the father and godfather; Knox himself had, as godfather to one of his sons, Whittingham, who had been his chief assistant in compiling the Book of Common Order, and who had also been his helper and fellow-worker at Geneva. The opinion of the Swiss reformers, as well as that of their Scotch followers, was in favor of the presence of sponsors in addition to the parents at the baptism of children. The parent having professed his desire to have his child baptized in the Christian faith, was addressed by the minister, and called upon to profess his own faith and his purpose to instruct his child in the same. Having repeated the Creed, the minister proceeded to expound the same as setting forth the sum of Christian doctrine, a prescribed prayer followed, the child was baptized, and the prayer of thanksgiving, also prescribed, closed the service. The Book of Common Order required that marriages should be celebrated in the Church and on the Lord's Day: "The parties assemble at the beginning of the sermon and the Minister at time convenient saith as followeth:" In the forms of exhortation and admonition to the contracting parties no liberty to vary the address is allowed the minister, but in the one prayer which formed a part of the service, viz., the blessing at the close of the ceremony it is ordered: "The Minister commendeth them to God in this _or such like sort_."