As they listen to the word proclaimed in the Sunday assembly, the faithful look to the Virgin Mary, learning from her to keep it and ponder it in their hearts (cf. Lk 2:19). With Mary, they learn to stand at the foot of the Cross, offering to the Father the sacrifice of Christ and joining to it the offering of their own lives. With Mary, they experience the joy of the Resurrection, making their own the words of the Magnificat which extol the inexhaustible gift of divine mercy in the inexorable flow of time: "His mercy is from age to age upon those who fear him" (Lk 1:50). From Sunday to Sunday, the pilgrim people follow in the footsteps of Mary, and her maternal intercession gives special power and fervour to the prayer which rises from the Church to the Most Holy Trinity.-JOHN PAUL II
"Sunday is a Catholic Institution, and its claims to observance can be defended only on Catholic principles. . . .From beginning to end of Scripture there is not a single passage that warrants the transfer of weekly public worship from the last day of the week to the first."
—The Catholic Press, Sydney, Australia, August, 1900.
"Protestantism, In discarding the authority of the (Roman Catholic) Church, has no good reasons for its Sunday theory, and ought logically to keep Saturday as the Sabbath."
—John Gilmary Shea, American Catholic Quarterly Review, January, 1883
"It is well to remind the Presbyterians, Baptists, Methodists, and all other Christians, that the Bible does not support them anywhere in their observance of Sunday. Sunday is an institution of the Roman Catholic Church, and those who observe the day observe a commandment of the Catholic Church."
—Priest Brady, in an address, reported in the Elizabeth, N.J. "News", March 18, 1903.
"Ques.- Have you any other way of proving that the (Catholic) Church has power to institute festivals of percept (to command holy days)?"
"Ans.- Had she not such power, she could not have done that in which all modern religionists agree with her: she could not have substituted the observance of Sunday the first day of the week, for the observance of Saturday the seventh day, a change for which there is no Scriptural authority."
—Stephan Keenan, A Doctrinal Catechism, page 176.
"Reason and common sense demand the acceptance of one or the other of these alternatives: either Protestantism and the keeping holy of Saturday, or Catholicity and the keeping holy of Sunday. Compromise is impossible."
—The Catholic Mirror, December 23, 1893.
"God simply gave His (Catholic) Church the power to set aside whatever day or days, she would deem suitable as Holy Days. The Church chose Sunday, the first day of the week, and in the course of time added other days, as holy days.
—Vincent J. Kelly, Forbidden Sunday and Feast-Day Occupations, page 2.
"Protestants. . .accept Sunday rather than Saturday as the day for public worship after the Catholic Church made the change. . .But the Protestant mind does not seem to realize that . . in observing the Sunday, they are accepting the authority of the spokesman for the church, the Pope."
—Our Sunday Visitor, February 5, 1950.
"We hold upon this earth the place of God Almighty."
—Pope Leo XIII, in an Encyclical letter, June 20, 1894.
"If Protestants would follow the Bible, they should worship God on the Sabbath Day. In keeping the Sunday, they are following a law of the Catholic Church."
—Albert Smith, chancellor of the Archdiocese of Baltimore, replying for the Cardinal in a letter, February 10, 1920.
"It was the Catholic Church which, by the authority of Jesus Christ, has transferred this rest (from the Bible Sabbath) to the Sunday. . .Thus the observance of Sunday by the Protestants is an homage they pay, in spite of themselves, to the authority of the (Catholic) Church."
—Monsignor Louis Segur, Plain Talk about the Protestantism of Today, page 2l3.
"We observe Sunday Instead of Saturday because the Catholic Church transferred the solemnity from Saturday to Sunday."
—Peter Geiermann, CSSR, A Doctrinal Catechism, 1957 edition, page 50.
"We Catholics, then, have precisely the same authority for keeping Sunday holy instead of Saturday as we have for every other article of our creed, namely, the authority of the Church. . .whereas you who are Protestants have really no authority for it whatever; for there is no authority for it (Sunday sacredness) in the Bible, and you will not allow that there can be authority for it anywhere else. Both you and we do, in fact, follow tradition in this matter; but we follow it, believing it to be a part of God’s word, and the (Catholic) Church to be its divinely appointed guardian and interpreter; you follow it (the Catholic Church), denouncing it all the time as a fallible and treacherous guide, which often ‘makes the commandments of God of none effect’ quoting Matthew 15:6."
—The Brotherhood of St. Paul, The Clifton Tracts, Vol. 4, tract 4, page 15.
Presbyterian: "There is no word, no hint in the New Testament about abstaining from work on Sunday. The observance of Ash Wednesday, or Lent, stands exactly on the same footing as the observance of Sunday. Into the rest of Sunday no Divine Law enters."
—Canon Eyton, in The Ten Commandments
Methodist: "It is true that there is no positive command for infant baptism. Nor is there any for keeping holy the first day of the week. Many believe that Christ changed the Sabbath. But, from His own words, we see that He came for no such purpose. Those who believe that Jesus changed the Sabbath base it only on a supposition."
—Amos Binney, Theological Compendium, pages 180-181
Baptist: "To me it seems unaccountable that Jesus, during three years’ discussion with His disciples, often conversing with them upon the Sabbath question, discussing it in some of its various aspects, freeing it from its false (Jewish traditional) glosses, never alluded to any transference of the day; also, that during the forty days of His resurrection life, no such thing was intimated. Nor, so far as we know, did the Spirit, which was given to bring to their remembrance all things whatsoever that He had said unto them, deal with this churches, counseling and instructing those founded, discuss or approach the subject.
"Of course I quite well know that Sunday did come into use in early Christian history as a religious day, as we learn from the Christian Fathers and other sources. But what a pity that it comes branded with the mark of Paganism, and christened with the name of the sun-God, then adopted and sanctified by the Papal apostasy, and bequeathed as a sacred legacy to Protestantism."
—Dr. E.T. Hiscox, report of his sermon at the Baptist Minister’s convention, in New York Examiner, November 16, 1893
In India, Sunday is Ravivar. It is based on Ravi - Vedic God of Sun.
Christianity adopted some of the attributes of the Sol Invictus religion, as apparent in the first examples of Christian iconography, depicting Christ with solar attributes such as the radiated crown or, in a few instances, a solar chariot.
Sol Invictus had been adopted by the Church of Rome as evidenced by Christ as Apollo-Helios in a mausoleum discovered under St. Peter's Basilica and dated to 250, and, from the beginning of the third century, "Sun of Justice" was used as a title of Christ.
The date for Christmas may also bear a relation to the sun worship. According to the Syriac bishop Jacob Bar-Salibi, writing in the twelth century:
"It was a custom of the Pagans to celebrate on the same 25 December the birthday of the Sun, at which they kindled lights in token of festivity. In these solemnities and revelries the Christians also took part. Accordingly when the doctors of the Church perceived that the Christians had a leaning to this festival, they took counsel and resolved that the true Nativity should be solemnised on that day." (cited in "Christianity and Paganism in the Fourth to Eighth Centuries", Ramsay MacMullen. Yale:1997, p155)
Cool, I was looking for some quotes from the church to describe Sunday opposed to what I normally get from people who are unaware of why Sunday is the 'day of rest'.