The Church of the Brethren observe Sunday (the Lord's Day) as the primary day of worship and gathering. Sunday commemorates Christ's resurrection and is central to Christian practice and community life.

The Sabbath principle—that God sanctifies time, that rest is important, that families and communities should gather—is affirmed. However, the Brethren do not enforce strict Sabbath observance (prohibitions on work, travel, etc.) in the manner of Seventh-day Adventists or Orthodox Judaism.

Sunday is recognized as a day for corporate worship, family time, and rest from labor, but the specific observances are matters of conscience rather than law. The emphasis is on the spiritual principle (rest, worship, community) rather than on detailed legal requirements.