Thank you for giving us an opportunity to explain these comments in greater detail.

Please note that the quotes in that sidebar were actually admissions from Catholic authorities and publications acknowledging the fact that the Roman Catholic Church replaced observance of the seventh-day (Saturday) Sabbath with Sunday, the first day of the week, based on church authority rather than Scripture.

While we agree with their admissions, which are well borne out in history, we strongly disagree that any person or church has the authority to change such a direct commandment from God—particularly one of the Ten Commandments.

As for the scriptural passages you mention, do they refer to worship on Sunday? In fact they do not, and the Bible nowhere shows the first-century apostles changing the seventh-day Sabbath to Sunday.

Each of these passages is thoroughly addressed and explained on pages 36-37 of our free booklet Sunset to Sunset: God's Sabbath Rest under the title "Was Sunday the New Testament Day of Worship?" Following are some of the essential points regarding these passages.

"One scripture commonly cited to justify Sunday worship is Revelation 1:10 Revelation 1:10I was in the Spirit on the Lord's day, and heard behind me a great voice, as of a trumpet,
American King James Version×, where John said, 'I was in the Spirit on the Lord's Day' . . . Nowhere does the Bible define 'Lord's Day' as the first day of the week . . . If this were referring to a day of the week, we would have to conclude that John meant the seventh day, since Jesus Christ said He was the 'Lord of the Sabbath' (Mark 2:28 Mark 2:28Therefore the Son of man is Lord also of the sabbath.
American King James Version×)."

As our Sabbath booklet further explains, this passage in context refers John's vision of the future period the Bible repeatedly calls "the Day of the Lord," a time when many end-time prophecies will be fulfilled. It is not referring to a day of the week.

The next scripture addressed is Acts 20:7 Acts 20:7And on the first day of the week, when the disciples came together to break bread, Paul preached to them, ready to depart on the morrow; and continued his speech until midnight.
American King James Version×about breaking bread. This term does not denote a religious service but the dividing of loaves of bread for eating a meal—as other New Testament passages show. Since days in the Bible begin and end at sunset (compare Genesis 1:5 Genesis 1:5And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
American King James Version×; Leviticus 23:32 Leviticus 23:32It shall be to you a sabbath of rest, and you shall afflict your souls: in the ninth day of the month at even, from even to even, shall you celebrate your sabbath.
American King James Version×), the events described in Acts 20 begin with a meal on Saturday evening after the Sabbath had ended (as several translations clearly show).

As our Sabbath booklet explains about this passage: "After speaking and talking all night [after sundown], Paul the next morning walked almost 20 miles to Assos to meet the rest of the people in his group who had sailed there (verses 11, 13-14). Rather than describing a religious service on Sunday, this passage actually documents Paul walking 20 miles on foot on the first day of the week—hardly making it a day of rest and worship for him!"

Now consider 1 Corinthians 16:1-2 1 Corinthians 16:1-2 [1] Now concerning the collection for the saints, as I have given order to the churches of Galatia, even so do you. [2] On the first day of the week let every one of you lay by him in store, as God has prospered him, that there be no gatherings when I come.
American King James Version×, widely assumed to be an offertory collection during a Sunday worship service. Although a collection did take place on the first day of the week, nowhere is it stated that a worship service was involved. This was actually a special circumstance—part of a wider famine-relief effort aimed at providing Church members in Judea with food supplies. As some Bible commentaries note, this appears to be the same relief effort mentioned in Acts 11:28-30 Acts 11:28-30 [28] And there stood up one of them named Agabus, and signified by the Spirit that there should be great dearth throughout all the world: which came to pass in the days of Claudius Caesar. [29] Then the disciples, every man according to his ability, determined to send relief to the brothers which dwelled in Judaea: [30] Which also they did, and sent it to the elders by the hands of Barnabas and Saul.
American King James Version×.

As the booklet explains: "These contributions were to be 'laid aside' and 'stored up,' not brought to a church service and collected there. To say this is an account of a collection taken up during a Sunday worship service is to read into the Bible an unwarranted personal interpretation."

Again, these three passages of Scripture are all explained in considerably greater detail in our free booklet Sunset to Sunset: God's Sabbath Rest.

What, then, of the idea that Jews are required to keep the Sabbath but Christians are not? After the creation of Adam and Eve, God rested on the seventh day and sanctified it—setting it apart as the Sabbath day (Genesis 2:1-3 Genesis 2:1-3 [1] Thus the heavens and the earth were finished, and all the host of them. [2] And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made. [3] And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.
American King James Version×). This was some 2,000 years before the Jewish people ever came on the scene.

Notice further what Leviticus 23:1-3 Leviticus 23:1-3 [1] And the LORD spoke to Moses, saying, [2] Speak to the children of Israel, and say to them, Concerning the feasts of the LORD, which you shall proclaim to be holy convocations, even these are my feasts. [3] Six days shall work be done: but the seventh day is the sabbath of rest, an holy convocation; you shall do no work therein: it is the sabbath of the LORD in all your dwellings.
American King James Version×says regarding ownership of the Sabbath: "And the LORD spoke to Moses, saying, 'Speak to the children of Israel, and say to them: The feasts of the LORD, which you shall proclaim to be holy convocations [mandatory sacred assemblies], these are My feasts. Six days shall work be done, but the seventh day is a Sabbath of solemn rest, a holy convocation. You shall do no work on it; it is the Sabbath of the Lord in all your dwellings" (emphasis added throughout).

Here God repeatedly emphasizes that the Sabbath belongs to Him, not to any particular group of people. As for whom it was made, Jesus said "the Sabbath was made for humankind" (Mark 2:27 Mark 2:27And he said to them, The sabbath was made for man, and not man for the sabbath:
American King James Version×, New Revised Standard Version)—that is, for all people, not just the Jews.

Another key to understanding the Sabbath as the day all Christians should observe is the often-overlooked fact that it is one of the Ten Commandments. Exodus 20:11 Exodus 20:11For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: why the LORD blessed the sabbath day, and hallowed it.
American King James Version×shows that the rationale for keeping it is based on the fact that God rested, blessed and hallowed the seventh day at creation, which concerns all humanity, not just the Jewish people. (Request our free booklet The Ten Commandments, noting especially pages 31–36.)

Again, if you carefully read and study our free booklet Sunset to Sunset: God's Sabbath Rest, you will discover that the significance and importance of this particular day is discussed from practically every possible angle.