How Do We Know Sunday is the Christian Day of Worship?

By R. W. McAlister

    In the Greek language, the names of the days Monday, Tuesday, Wednesday, and Thursday mean "second", "third", "fourth", and "fifth" respectively. This leaves Sunday as the first day of the week. The current Greek name for Sunday, Κυριακή (Kyriake), means “Lord’s Day” coming from the word Κύριος (Kyrios), which is the Greek word for “Lord” (Acts 20:7; I Cor. 16:2) 
    Some hold – even today – that the Sabbath is the day for Christian worship, but where is the evidence that the early church, under the Lord’s guidance, came together to worship God on the Sabbath day? 
    The kingdom of Christ was established on the day of Pentecost (Acts 2:1), which always fell on “the morrow after the Sabbath” (Lev. 23:15-16), hence, on Sunday. So the church started out meeting for worship on the first day of the week (Acts 2:42). 
    Consider Acts 20:7: “And upon the first day of the week, when the disciples came together to break bread, Paul preached unto them, ready to depart on the morrow; and continued his speech until midnight.” Some English translations, such as the King James, say, “when the disciples came together.” In the original language, the meaning is better rendered, “The disciples were gathered together” (that’s in the passive voice) upon “the first day of the week” to break bread, i.e., to worship, (Acts 20:7). The specific day of meeting was no accident. Though Paul was anxious to get to Jerusalem (Acts 20:16), he waited seven days for the opportunity to assemble with the church. 
    Moreover, the passive voice indicates that the assembling together was instituted by someone other than the disciples. It was by God’s design. 
    According to I Cor. 16:2, the saints in Corinth were assembling and contributing into the church treasury, “every first day of the week.” 
    On the isle of Patmos, John was “in the spirit” on “the Lord’s day” (Rev. 1:10). The term for “Lord’s” is kupiakos, which is defined here as “relating to the Lord.” Thayer’s Greek Lexicon says: “the day devoted to the Lord, sacred to the memory of Christ’s resurrection.” In other words, Sunday, the first day of the week. Dear Soul, where are you normally found on the first day of the week when the saints assemble?

 - R. W. McAlister preaches for the Anna Church of Christ in Anna, IL.He may be contacted through the congregation's website: http://www.annachurchofchrist.com/