Iglesia ni Cristo denies that Christians are obligated to observe the Sabbath (Saturday). The Old Testament Sabbath law is understood as part of the ceremonial law of Moses that is no longer binding on New Testament believers. Instead, INC practices Sunday worship, commemorating the Lord's resurrection on the first day of the week. This is understood as consistent with New Testament practice and the discontinuation of Jewish ceremonial observances for Christians.

The Sabbath day restrictions are explicitly rejected as not applicable to Christians. Sunday is the day of corporate worship and religious observance in INC. This doctrine represents a firm rejection of Seventh-day Adventist and other Sabbatarian theologies. The change from Saturday to Sunday worship is presented as a divinely authorized transition from Old Testament to New Testament practice.