VaultAI Summary: This sermon examines Hebrews 4 to explain the theological shift of Sabbath observance from the seventh day to the first day of the week. It argues that the seventh-day rest, associated with creation, is inaccessible to sinners due to the broken covenant, whereas the first day signifies the completed work of redemption and Christ's resurrection. The text presents a parallel between God's rest after creation and Christ's rest after redemption, establishing the Lord's Day as the divinely appointed sign of the people of God. The preacher warns against Judaizing practices that reject this new covenant sign and emphasizes that true Sabbath keeping involves entering into Christ's rest through faith. Finally, the sermon exhorts believers to labor to enter this rest by persevering in faith, finding spiritual nourishment and strength for the week ahead through the proclamation of the gospel on the Lord's Day.