That christian families are sanctified to God I prove thus: 1. A society of holy persons must needs be a holy society. But a family of christians is a society of holy persons; therefore, 2. We find in Scripture not only single persons, but the societies of such, sanctified to God. Deut. vii. 6, "Thou art an holy people unto the Lord thy God; he hath chosen thee to be a special people to himself above all people that are upon the face of the earth." So Deut. xiv. 20, 21. So the body of that commonwealth did all jointly enter into covenant with God, and God to them, Deut. xxix.; xxx.; and xxvi. 17-19, "Thou hast vouched the Lord this day to be thy God, and to walk in his ways; and the Lord hath vouched thee this day to be his peculiar people, that thou mayst be an holy people to the Lord." So chap. xxviii. 9; Dan. viii. 24; xii. 7. Joshua, chap. xxiv. devoteth himself and his house to the Lord; "I and my house will serve the Lord." And Abraham by circumcision (the covenant, or seal of the covenant of God) consecrated his whole household to God; and so were all families after him to do (as to the males, in whom the whole was consecrated). And whether besides the typifying intent, there were not somewhat more in the sanctifying of all the first-born to God, who if they lived, were to be the heads of the families, may be questioned.
The passover was a family duty, by which they were yet further sanctified to God. Yea, it is especially to be observed how in the New Testament, the Holy Ghost doth imitate the language of the Old, and speak of God's people as of holy societies, as the Jews were. As in many prophecies it was foretold that nations and kingdoms should serve him (of which I have spoken more in my book of Baptism); and among those who should "mourn over him whom they have pierced" in gospel times, when the spirit of grace and supplication is poured forth, are "the family of the house of David apart, and their wives apart; the family of the house of Nathan apart, and their wives apart; every family, even all the families that remained, apart, and their wives apart," Zech. xi. 12-14. So Christ sendeth his disciples to "baptize nations," having discipled them; and "the kingdoms of the world shall become the kingdoms of the Lord, and his Christ." And as, Exod. xix. 5, 6, God saith of the Jews, "Ye shall be a peculiar treasure to me above all people; and ye shall be unto me a kingdom of priests, and a holy nation;" so doth Peter say of all christians, 1 Pet. ii. 5-7, 9, "Ye also, as living stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices acceptable to God by Jesus Christ. But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people, that you should show forth the praises of him that hath called you out of darkness into his marvellous light." Mark how fully this text doth prove all that we are about. It speaks of christians collectively, as in societies, and in societies of all the most eminent sorts: "a generation;" which seems especially to refer to tribes and families: "a priesthood, nation, people;" which comprehendeth all the orders in the nation ofttimes. And in all these respects they are holy, and peculiar, and chosen, to show, that God's people are sanctified in these relations and societies. And then mark the end of this sanctification; ver. 5, "to offer up spiritual sacrifices acceptable to God by Jesus Christ;" ver. 9, "to show forth the praises of him that hath called you," &c.