If the Lord's Day is Sunday, then why is not the Lord's Day the Sabbath? "I was in the Spirit on the Lord's Day, and heard behind me a great voice, as of a trumpet." (Revelation 1:10) John here simply states that he "was in the Spirit on the Lord's day." Although it is true that eventually the term "Lord's day" came to be used for Sunday, no evidence indicates this was the case until about a century after the Book of Revelation was written! In fact, there is likelihood that the term was applied to "Easter" Sunday before it was applied to a weekly Sunday.

But the Roman province of Asia, to which the Revelation applies, had no Sunday-Easter tradition, either at the time the Revelation was written or even a century later. Thus "Lord's day" in Revelation 1:10 could not refer to an Easter Sunday.

Most pointedly of all, there is neither prior nor contemporary evidence that Sunday had achieved in New Testament times a status which would have caused it to be called "Lord's day." Another day - the seventh-day Sabbath - had been the Lord's holy day from antiquity (see Isaiah 58:13) and was the day on which Christ Himself and His followers, including the Apostle Paul had attended religious services.

The Book of Acts reveals that the only day on which the Apostles repeatedly were engaged in worship services on a weekly basis was Saturday, the seventh day of the week. The Apostle Paul and his company, when visiting Antioch in Pisidia, "went into the synagogue on the Sabbath day, and sat down." (Acts 13:14) After the Scripture reading, they were called upon to speak. They stayed in Antioch a further week, and that "next Sabbath day came almost the whole city together to hear the word of God." (Acts 13:44)

In Philippi, Paul and his company went out of the city by a riverside on the Sabbath day, to the place where prayer was customarily made (Acts 16:13). In Thessalonica, "as his manner was," Paul went to the synagogue and "three Sabbath days reasoned with them out of the scriptures." (Acts 17:2) And in Corinth, where Paul resided for a year and a half, "he reasoned in the synagogue every Sabbath and persuaded the Jews and the Greeks" (Acts 18:4)

Thus the evidence in the Book of Acts multiplied regarding apostolic attendance at worship services on Saturday.

In sum total, there is not one piece of concrete evidence anywhere in the New Testament that Sunday was considered as a weekly day of worship for Christians. Rather, Christ Himself, His followers at the time of His death, and apostles after His resurrection regularly attended services on Saturday the seventh day of the week.

The question now arises as to when and how Christian Sunday observance arose. This is a vital question because we know that Sunday is not the "Lord's Day."

Author's Bio: 

Get 5 Free Sabbath Lessons and learn Why Do Christians Celebrate The Sabbath on Sunday, The Purpose of The Sabbath, and The Sabbath Truth at http://www.asabbathwarning.com by Sidney D. Butler, author of A Sabbath Warning.