[The Puritans] regarded their [Anglican] opponents’ habit of discriminating between essentials and nonessentials as a dangerous procedure. Dangerous, not because it claimed to exalt Christ and the Gospel to the supreme place, but because it failed to emphasize that the New Testament offers no safety to those who knowingly neglect the least of Christ’s commandments.
Samuel Rutherford says: “We urge the immutability of Christ’s laws, as well in the smallest as greatest things, though the commandments of Christ be greater or less in regard to the intrinsical matter, as to use water in baptism, or to baptize is less than to preach Christ, and believe in him, 1 Cor 1:17. Yet they are both alike great, in regard of the authority of Christ the Commander, Matt. 28:18–19. And it’s too great boldness to alter any commandment of Christ for the smallness of the matter, for it lieth upon our conscience not because it is a greater or a lesser thing…but it teeth us for the authority of the law-giver: Now God’s authority is the same when he saith, You shall not worship false gods, and when he saith, You shall not add of your own ring or pin to the Ark, Tabernacle, Temple [Exod 25:9; Deut 4:2?], yea, either to break or teach others to break one of the least of the commandments of God, maketh men the least in the Kingdom of God, Matt. 5:18…. The fact that a man may be defective in knowledge and practice, and yet be saved through being on the foundation which is Christ, provides no warrant for dividing up Scipture into essentials and nonessentials—placing rules concerning the visible church in the second category, as though they could be safely left unkept (“Scripture and 'Things Indifferent,'” in Puritan Papers, vol. 3, pp. 28–29).