Why Don't We Keep the Day of Atonement (or other "forever" days)?

Someone in the congregation wrote:

Ok, I'm in Leviticus 16. It says this is a statute forever in verse 31 and in verse 34 it says this shall be an everlasting statute for you. Why don't we celebrate Yom Kippur? Is it because it says the priest shall make atonement for the people, the children of Israel for all their sins once a year? But Christ has already made atonement for us?

Since I often get such questions, I thought that my reply (below) might be helpful to others:

Good question. And praise God for giving you the good, Scripture wisdom to go straight to Christ Himself for resolving the answer.

(1) "forever" is the word "olam" which can mean anything from "a really long time" to "for everlasting eternity"

(2) The "for you" is specific to the administration under Moses that established the nation of Israel as a church at Sinai. The "you" in "everlasting statue for you" of v34 no longer exists. That way of constituting the church has been finally and fully rejected by God, Who has replaced the church as constituted in Moses with the church as constituted in Christ. This is one of the main points of the entire book of Hebrews, as well as important passages (Col 2:16–17 and other places) that explain why the ceremonial shadows from under Moses are not to be followed any longer. (important to remember here that although special Sabbaths from under Moses have been canceled with the cancellation of that church, the holiness of the Sabbath unto Yahweh was before the Mosaic administration and continues after it)

(3) More specific to the day of atonement itself, it is eternally/permanently fulfilled on the GREAT DAY of atonement. It was an annual ritual for consecration of earthly copies, but Jesus's atonement has consecrated the true and eternal worship of which those were a copy (Heb 7:11–10:18). 

Since the copies are gone, they also don't need to be consecrated annually with blood. No one can actually observe Yom Kippur, because there is no high priest, and there can be no more sacrifice. God took away these things. But the sacrifice, and the application of the blood in the Holy of Holies is the main essence of the day; without it, people observing it "in their hearts" or "in their homes" is utterly meaningless. 

And when they continue to do so today, they sin against Christ's High Priesthood, they sin against Christ's once-for-all sacrifice, they sin against the great commission which commands that the church now be constituted of many nations, they sin against the Lord's Day which is the only consecrated day in Christ's church, they sin against Heaven by participating in the rituals of the copy over/against the worship that connects with the reality. 

The only holy day is the day of Christ Himself, the Lord's Day. Christ Himself is clearly seen as Yahweh Himself by the fact that it is one and the same now to remember and keep consecrated the Lord's Day and to remember and keep Yahweh's holy day. To put it in language almost too crass: Yahweh Day was before all of the consecrated days of the church in its infancy, and continued with all the consecrated days of the church in its infancy (e.g. the Mosaic administration), but in part to show that Christ is Yahweh and not a mere man like Moses, the church is now to observe only Yahweh Day which is Jesus Day, i.e. THE LORD'S DAY. So, the keeping of the old days combines offense against Christ Himself with the horrible sin of violating the fourth commandment.

Many believers have some sort of sincerity in attempting an observance of the day of atonement. And when the temple still stood, the New Testament commanded patience with such (Rom 14:1–13). There is much less room for conscientious observance now that God Himself has literally, physically destroyed the possibility of such observance in 70 a.d., as He prophesied that He would in Heb 10:9. But we would still do well to maintain that spirit of patience as we help these observers out of a less-excusable ignorance and a wickedness that is a great offense against God and great harm to the believer. 

And much of the rest of the church have no stone to throw, since they observe things like advent, lent, "easter," etc. At least those who attempt to keep the day of atonement are keeping something that God had at one point commanded. It is good to maintain a spirit of patience with these manmade-day observers as well. But if there is a need for instruction for the former group, how much more need there is for instruction with this group!

Christ Himself is our Great High Priest.

Christ Himself offered His own blood, once for all for our atonement.

Christ Himself has consecrated the very worship of 

Heaven itself by that blood.

Christ Himself, from Heaven, leads an international (pan-national!) church

on the Day of Christ Himself.

These are the emphases to maintain in correcting this error. And you can see the great theme in all of them: Christ Himself! 

This is why the book that urges diligent attendance upon the Sabbath-keeping that remains, and the parts of the worship of that day's assembly, in which it participates with the assembly in glory... that entire book begins with one of the most exalted descriptions of CHRIST HIMSELF.

———

n.b. some relevant sections in our Confession

WCF 17.5–6
5. This covenant was differently administered in the time of the law, and in the time of the gospel: under the law, it was administered by promises, prophecies, sacrifices, circumcision, the paschal lamb, and other types and ordinances delivered to the people of the Jews, all foresignifying Christ to come; which were, for that time, sufficient and efficacious, through the operation of the Spirit, to instruct and build up the elect in faith in the promised Messiah, by whom they had full remission of sins, and eternal salvation; and is called the old testament.

6. Under the gospel, when Christ, the substance, was exhibited, the ordinances in which this covenant is dispensed are the preaching of the Word, and the administration of the sacraments of baptism and the Lord's Supper: which, though fewer in number, and administered with more simplicity, and less outward glory, yet, in them, it is held forth in more fullness, evidence and spiritual efficacy, to all nations, both Jews and Gentiles; and is called the new testament. There are not therefore two covenants of grace, differing in substance, but one and the same, under various dispensations.

WCF 19.3
3. Beside this law, commonly called moral, God was pleased to give to the people of Israel, as a church under age, ceremonial laws, containing several typical ordinances, partly of worship, prefiguring Christ, his graces, actions, sufferings, and benefits; and partly, holding forth divers instructions of moral duties. All which ceremonial laws are now abrogated, under the new testament.

WCF 21.7

7. As it is 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.