The Advent Truth
If Revelation 1:10 is supposed to prove Sunday is the Lord’s Day, then where is the verse that actually says so?

The problem is not that Sunday advocates have a verse calling Sunday “the Lord’s Day.” The problem is that they don’t.

Not one text in Scripture ever defines Sunday as the Lord’s Day.

Meanwhile, the Bible repeatedly identifies the seventh-day Sabbath as belonging uniquely to the Lord:

• Exodus 20:10 — “The seventh day is the sabbath of the LORD thy God.”
• Isaiah 58:13 — God calls the Sabbath “my holy day.”
• Matthew 12:8 — Jesus says He is “Lord even of the sabbath day.”
• Mark 2:27-28 — The Sabbath was made for mankind, and Jesus is Lord of it.
• Luke 6:5 — The Son of Man is Lord of the Sabbath.

When Scripture defines its own terms, we should let Scripture speak for itself.

Think about it this way: if someone asked, “What is the Lamb of God?” you wouldn’t answer with church tradition. You would go to the verses that define the phrase. If someone asked, “What is the Day of Atonement?” you would go to the passages that identify it. So why should “the Lord’s Day” be any different?

The strongest case for Sunday in Revelation 1:10 is not a Bible verse—it is an assumption imported into the text. John never says “Sunday.” He never says “the first day of the week.” He simply says “the Lord’s Day.”

The question then becomes: What day does the Lord Himself claim as His own?

The answer appears over and over again throughout Scripture: the Sabbath.

This is not about winning arguments. It is about allowing the Bible to define its own language rather than redefining it through later tradition.

If you can find a verse that explicitly says Sunday is the Lord’s Day, I’m willing to read it. But until then, the biblical evidence points in one direction: the day God calls His, the day Jesus claims Lordship over, and the day repeatedly identified as belonging to the Lord is the seventh-day Sabbath.

Test everything by Scripture.