Heidelberg Catechism - Lord's Day 38

103. Q . What is God’s will for you in the fourth commandment?
        A. First, that the gospel ministry and education for it be maintained, and that, especially on the festive day of rest, I diligently attend the assembly of God’s people to learn what God’s Word teaches, to participate in the sacraments, to pray to God publicly, and to bring Christian offerings for the poor.

Second, that every day of my life I rest from my evil ways, let the Lord work in me through his Spirit, and so begin in this life the eternal Sabbath.