The same way Jesus used illustrations and storytelling on earth to help us understand what He was doing for us in Heaven, He also used rituals and symbols ("types") here on earth to point forward the antitype.
The same is true for many of the rituals of the Israelites, they pointed forward to Jesus and the work He is doing in the Heavenly Sanctuary.
“The whole system of types and symbols was a compacted prophecy of the gospel, a presentation in which were bound up the promises of redemption.” Acts of Apostles (AA 14.1)
“And when a stranger shall sojourn with thee, and will keep the passover to the Lord, let all his males be circumcised, and then let him come near and keep it; and he shall be as one that is born in the land: for no uncircumcised person shall eat thereof.”
“Thus saith the Lord God; No stranger, uncircumcised in heart, nor uncircumcised in flesh, shall enter into my sanctuary, of any stranger that is among the children of Israel.”
The Passover is linked to circumcision, which became obsolete in the Christian church.
“For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh.”
So is the passover still valid? How did John describe it?
“And the passover, a feast of the Jews, was nigh.”
Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands; That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world: But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ. For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us; Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace... ” Ephesians 2:11-15
“In this ordinance, Christ discharged his disciples from the cares and burdens of the ancient Jewish obligations in rites and ceremonies. These no longer possessed any virtue; for type was meeting antitype in himself, the authority and foundation of all Jewish ordinances that pointed to him as the great and only efficacious offering for the sins of the world.”
RH June 14, 1898, par. 15
“Christ was standing at the point of transition between two economies and their two great festivals. He, the spotless Lamb of God, was about to present Himself as a sin offering, that He would thus bring to an end the system of types and ceremonies that for four thousand years had pointed to His death. As He ate the Passover with His disciples, He instituted in its place the service that was to be the memorial of His great sacrifice. The national festival of the Jews was to pass away forever. The service which Christ established was to be observed by His followers in all lands and through all ages.”
RH June 14, 1898, par. 15
“The death of Jesus Christ for the redemption of man, lifts the veil and reflects a flood of light back hundreds of years, upon the whole institution of the Jewish system of religion. Without the death of Christ all this system was meaningless. The Jews reject Christ, and therefore their whole system of religion is to them indefinite, unexplainable, and uncertain. They attach as much importance to shadowy ceremonies of types which have met their antitype, as they do to the law of the ten commandments, which was not a shadow, but a reality as enduring as the throne of Jehovah. The death of Christ elevates the Jewish system of types and ordinances, showing that they were of divine appointment, and for the purpose of keeping faith alive in the hearts of his people.”
RH May 6, 1875, par. 17
“Then by the stoning of Stephen the Jews finally sealed their rejection of the gospel.”
Desire of Ages (DA 233.3)
It should not be overlooked that after the close of the 69th and 70th weeks, the rituals which pointed forward to Christ were completed. Type met Antitype. Christianity was formed and Israel and it's rituals became a thing of the past.
“I will also cause all her mirth to cease, her feast days, her new moons, and her sabbaths, and all her solemn feasts.”
“Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross; And having spoiled principalities and powers, he made a shew of them openly, triumphing over them in it. Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days.”
“To what purpose is the multitude of your sacrifices unto me? saith the Lord: I am full of the burnt offerings of rams, and the fat of fed beasts; and I delight not in the blood of bullocks, or of lambs, or of he goats.”
“Bring no more vain oblations; incense is an abomination unto me; the new moons and sabbaths, the calling of assemblies, I cannot away with; it is iniquity, even the solemn meeting. Your new moons and your appointed feasts my soul hateth: they are a trouble unto me; I am weary to bear them.”
We should not hang on to the Old Covenant of works!
“But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? Ye observe days, and months, and times, and years...”
E.G. White endorses the idea of having annual gatherings. Notice in the quote below she does not call them 'the' but 'a' Feast.
“Well would it be for the people of God at the present time to have a Feast of Tabernacles--a joyous commemoration of the blessings of God to them.”
Patriarchs & Prophets (PP 540.6)
The Feast of Tabernacles are now modern day Adventist Campmeetings. There has been a modernization of the Feasts:
“In the place of the national festival which the Jewish people had observed, He instituted a memorial service, in the ceremony of feet washing, and the sacramental supper, to be observed by His followers through all time and in every country.”
12LtMs, Ms 43, 1897, par. 24
“The symbols of the Lord's house are simple and plainly understood, and the truths represented by them are of the deepest significance to us. In instituting the sacramental service to take the place of the Passover, Christ left for his church a memorial of his great sacrifice for man. "This do," he said, "in remembrance of me." This was the point of transition between two economies and their two great festivals. The one was to close forever; the other, which he had just established, was to take its place, and to continue through all time as the memorial of his death.”
RH, May 31, 1898 par. 2
“Christ gave his disciples to understand that the washing of their feet did not cleanse away their sin, but that the cleansing of their heart was tested in this humble service. If the heart was cleansed, this act was all that was essential to reveal the fact. He had washed the feet of Judas; but he said, “Ye are not all clean.” Judas brought a traitor's heart to this scene, and Christ revealed to all that he knew him to be the betrayer of his Lord, and that the washing of his feet was not an ordinance to cleanse the soul from its moral defilement.”
RH June 14, 1898, par. 7
“When this simple ordinance is being performed, the followers of Christ should bear in mind that this is the time for all to search their hearts to see if they are willing to humble themselves in spirit, and follow the example of Christ.”
RH June 14, 1898, par. 12
“The ordinance of feet washing most forcibly illustrates the necessity of true humility. While the disciples were contending for the highest place in the promised kingdom, Christ girded Himself, and performed the office of a servant by washing the feet of those who called Him Lord. He, the pure, spotless Lamb of God, was presenting Himself as a sin-offering; and as He now ate the Passover with His disciples, He put an end to the sacrifices which for four thousand years had been offered.”
12LtMs, Ms 43, 1897, par. 24