I don't know if you need much other than Chris' response.
The Confessed doctrine of the Presbyterians:
WCF 21.7
Of Religious Worship and the Sabbath DayVII. As it is of the law of nature, that, in general, a due proportion of time be set apart for the worship of God; so, in his Word, by a positive, moral, and perpetual commandment, binding all men in all ages, he hath particularly appointed one day in seven for a Sabbath, to be kept holy unto him: which, from the beginning of the world to the resurrection of Christ, was the last day of the week; and, from the resurrection of Christ, was changed into the first day of the week, which in Scripture is called the Lord's Day, and is to be continued to the end of the world as the Christian Sabbath.
1. The fourth commandment does not set a day to be observed, but rather how the day is to be observed. I'm still having a little bit of trouble saying that to get the day wrong is sinful when the commandment seems to be focused more on how the day is to be observed. Are we supposed to look for another commandment as to which day is to be observed? Could it be that Christ and the apostles set the new day for the purpose of church order, rather than as an inherent part of the commandment?
As Chris stated, the 4C stands with and after the 2C; which former teaches us to expect that God should be precise on the question, since it is his worship that is under discussion.
But, in fact the 4C--being a summary of God's ubiquitous moral law, yet
for Israel on that occasion--it
did specify the Old Covenant day when it states that among them called of God: "...the
seventh day is a Sabbath to the LORD your God." So far from being a thing indifferent (adiaphoron), it is proved consistent to the regulative principle: that where worship is concerned, we are to give God all that he asks, and only that which he asks.
God set the day on which he called his people to sacred assembly before him.
And therefore, IF the day may be changed (being a
positive aspect of the law), ONLY God has the authority to change it. He HAS changed it; therefore we continue to keep the moral command according to HOW he directs (as with all other essentials of worship: Word, sacrament, and prayer).
No, it is not the case that the apostles had any part in designating the day, as if
their concern for order was paramount. Nor is it the case that Christ makes a "suggestion" out of the same concern. The Apostles were together quite a bit between the Lord's death and Pentecost. Now whenever the Day is noted when Christ (that is, when GOD) met with the disciples--with the exception of the day of Ascension--it was the First Day. After the Ascension, they were meeting practically 'round the clock, and when does God (in Christ, by his Spirit) meet with them again? On the First Day, which was Pentecost. Is there a pattern here? The Reformed churches have agreed, yes; and this appears validated by the rest of the NT notices.
Therefore, Christ, by his local minister, calls the people to worship; not by the "traditions of our fathers," not by convenience set by our culture, but by divine institution.
2. What part of the fourth commandment is ceremonial and what part moral?
By "ceremonial" we mean: specifically related to Old Covenant observances. The commandment itself is moral, through and through. That which was "positive" is not ceremonial as such; but rather is a specific direction as to how to keep a commandment. In other words, "ceremony" was attached to the Sabbath in the ceremonial days of the Old Covenant.
Two commemorations are assigned to the 4C (Ex.20:11; Dt.5:15). The first is Creation, and the pattern set there (including following the 7th-day rest of God) is enjoined. The second is Redemption; in Israel's case it was being brought out of Egypt, which not-coincidentally took place on the 15th of the 1st month, by my reckoning a Sabbath day (supposing the Lord ordained the beginning of their calendar on the Sabbath, Ex.12:2, that their exodus should take place properly on that day).
Whether that opinion be taken as the truth or not, it is indisputable that our Lord--whose lordship of his people's Sabbath is plainly asserted Mt.12:8--completed our redemption on the First Day (see Lk.9:31 for our Lord's "exodus"), and even kept the last Old Covenant Sabbath perfectly in the tomb. The "Lord's Day" (Rev.1:10) is the great day of Redemption, and our weekly commemoration of it is not only fitting to the occasion; it corresponds to Israel's second commemoration, and well marks history forward from the cross; just as the 7th day well marked history until the cross.
