Acts 15:22-29.
The Council’s Letter to Gentile Believers
22 Then the apostles and elders, with the whole church, decided to choose some of their own men and send them to Antioch with Paul and Barnabas. They chose Judas (called Barsabbas) and Silas, men who were leaders among the believers. 23 With them they sent the following letter:
The apostles and elders, your brothers,
To the Gentile believers in Antioch, Syria and Cilicia:
Greetings.
24 We have heard that some went out from us without our authorization and disturbed you, troubling your minds by what they said. 25 So we all agreed to choose some men and send them to you with our dear friends Barnabas and Paul— 26 men who have risked their lives for the name of our Lord Jesus Christ. 27 Therefore we are sending Judas and Silas to confirm by word of mouth what we are writing. 28 It seemed good to the Holy Spirit and to us not to burden you with anything beyond the following requirements: 29 You are to abstain from food sacrificed to idols, from blood, from the meat of strangled animals and from sexual immorality. You will do well to avoid these things.
Farewell.
These men who claim they are authorized to change Gods Word were around even back then and they got into the church like wolves among sheep, and have been doing what they no claim they have authority to do.
The following is from the CATECHISM OF THE CATHOLIC CHURCH.
Sunday- fulfillment of the sabbath
2175 Sunday is expressly distinguished from the sabbath which it follows chronologically every week;
for Christians its ceremonial observance replaces that of the sabbath. In Christ's Passover, Sunday fulfills the spiritual truth of the Jewish sabbath and announces man's eternal rest in God. For worship under the Law prepared for the mystery of Christ, and what was done there prefigured some aspects of Christ:[107]
Those who lived according to the old order of things have come to a new hope,
no longer keeping the sabbath, but the Lord's Day, in which our life is blessed by him and by his death.[108]
2176 The celebration of Sunday observes the moral commandment inscribed by nature in the human heart to render to God an outward, visible, public, and regular worship "as a sign of his universal beneficence to all."[109]
Sunday worship fulfills the moral command of the Old Covenant, taking up its rhythm and spirit in the weekly celebration of the Creator and Redeemer of his people.
A day of grace and rest from work
2184
Just as God "rested on the seventh day from all his work which he had done,"[121] human life has a rhythm of work and rest. The institution of the Lord's Day helps everyone enjoy adequate rest and leisure to cultivate their familial, cultural, social, and religious lives.[122]
2185 On Sundays and other holy days of obligation, the faithful are to refrain from engaging in work or activities that hinder the worship owed to God, the joy proper to the Lord's Day, the performance of the works of mercy, and the appropriate relaxation of mind and body.[123] Family needs or important social service can legitimately excuse from the obligation of Sunday rest. The faithful should see to it that legitimate excuses do not lead to habits prejudicial to religion, family life, and health.
The charity of truth seeks holy leisure- the necessity of charity accepts just work.[124]
2186 Those Christians who have leisure should be mindful of their brethren who have the same needs and the same rights, yet cannot rest from work because of poverty and misery. Sunday is
traditionally consecrated by Christian piety to good works and humble service of the sick, the infirm, and the elderly. Christians will also
sanctify Sunday by devoting time and care to their families and relatives, often difficult to do on other days of the week. Sunday is a time for reflection, silence, cultivation of the mind, and meditation which furthers the growth of the Christian interior life.
2187
Sanctifying Sundays and holy days requires a common effort. Every Christian should avoid making unnecessary demands on others that would hinder them from observing the Lord's Day. Traditional activities (sport, restaurants, etc.), and social necessities (public services, etc.), require some people to work on Sundays, but everyone should still take care to set aside sufficient time for leisure. With temperance and charity the faithful will see to it that they avoid the excesses and violence sometimes associated with popular leisure activities. In spite of economic constraints, public authorities should ensure citizens a time intended for rest and divine worship. Employers have a similar obligation toward their employees.
2188 In respecting religious liberty and the common good of all,
Christians should seek recognition of Sundays and the Church's holy days as legal holidays. They have to give everyone a public example of prayer, respect, and joy and defend their
traditions as a precious contribution to the spiritual life of society. If a country's legislation or other reasons require work on Sunday, the day should nevertheless be lived as the day of our deliverance which lets us share in this "festal gathering," this "assembly of the firstborn who are enrolled in heaven."[125]
IN BRIEF
2189 "Observe the sabbath day, to keep it holy" (Deut 5:12). "The seventh day is a sabbath of solemn rest, holy to the Lord" (Ex 31:15).
2190
The sabbath, which represented the completion of the first creation, has been replaced by Sunday which recalls the new creation inaugurated by the Resurrection of Christ.
2191 The Church celebrates the day of Christ's Resurrection on the "eighth day," Sunday, which is rightly called the Lord's Day (cf. SC 106).
2192
"Sunday . . . is to be observed as the foremost holy day of obligation in the universal Church" (CIC, can. 1246 # 1). "On Sundays and other holy days of obligation the faithful are bound to participate in the Mass" (CIC, can. 1247).
It just goes on and on, but notice they correctly state
"Observe the sabbath day, to keep it holy" (Deut 5:12). "The seventh day is a sabbath of solemn rest, holy to the Lord" (Ex 31:15).
