Jesus was asked, what is the great commandment of the Law.
"Jesus said to him, 'You shall love the LORD your God with all your heart, with all your soul, and with all your mind.' This is the first and great commandment. And the second is like it: 'You shall love your neighbor as yourself.' On these two commandments hang all the Law and the Prophets" (Matthew 22:37-40). In answering, Jesus was quoting the Old Testament scriptures (Deuteronomy 6:5, Leviticus 19:18). "The Law and the Prophets" is a reference to the Old Testament scriptures, which are composed of the "law" (the books of Moses, the first five books of the Bible), the "prophets" (books such as Isaiah, Jeremiah, and Ezekiel as well as the other prophets), and the "writings" (such as Psalms). Jesus is saying that the Old Testament scriptures are based on love towards God and love towards neighbor.
The two great commandments are further defined by the ten commandments. The ten commandments fill in details about HOW to love God and love our neighbor. The first four of the ten commandments teach us how to love God, and the last six teach us how to love our neighbor. Then the whole rest of the Bible further teaches us how to practice the way of love and how to keep God's commandments in their practical application in our lives.
The fourth of the ten commandments teaches us to observe the seventh day Sabbath. As God counts days from sunset to sunset (Genesis 1:2, Leviticus 23:32), this would be from Friday sunset to Saturday sunset. During this time we are to refrain from work (Exodus 20:8, Deuteronomy 5:12) and not pursue our own entertainment (Deuteronomy 5:13-14). This is a time for drawing closer to God and assembling with other Christians for fellowship and instruction (Leviticus 23:3).
How does observance of the seventh-day Sabbath express love towards God? By obeying the Sabbath command, we are acknowledging God as our Creator and as our Lord who has authority over us. We acknowledge God's authority by believing and obeying what He commands in the fourth commandment. "Lord" means ruler, one who has authority. Many people call God "Lord", but it is those who really strive to believe and obey what God says who are acknowledging by their actions that the true God is their Lord (Luke 6:46). The fourth commandment has been called by some a "test" commandment, because it tests our willingness to believe God and obey Him (Exodus 16:4-5, 22-30). It is also a sign between God and his people (Exodus 31:12-13). A sign identifies. The Sabbath helps to identify to Christians who the true God is, that is, the God who created the earth, because the Sabbath day is a memorial of creation (Exodus 20:8-11). The Sabbath also identifies to God who His people are, because it is God's people who are willing to believe and obey what God says by keeping the Sabbath. Throughout the Bible, obedience to God's commandments is equated with love (John 14:21, 1 John 5:1-3).
The weekly Sabbath also illustrates the 7,000 year plan of God, for as the Sabbath follows the six days of work, so the millenial rule of Christ for 1,000 years will follow 6,000 years of man's rule over himself (2 Peter 3:8, Revelation 20:1-4, Daniel 12:4).
The Sabbath provides time for people to rest from the burdens and concerns of the week and draw closer to God in prayer and Bible study. Taking time to learn about the things of God and to draw closer to Him is also an expression of love towards God.
Keeping the Sabbath can also be a test of faith. Many people can figure out that it is wrong to murder, steal, commit adultery, etc. Even societies that do not have a culture based on the Bible can recognize that those things are wrong. But man cannot figure out on his own that it is wrong to work on the seventh day of the week. Man can only know that by believing what God says, and it takes faith to believe what God says, as Abraham did (Romans 4:3, James 2:23, Genesis 15:4-6, Isaiah 51:1-2), and faith is one of the weightier matters of the law (Matthew 23:23). In our day, it can be a test of faith for a man or woman to keep the Sabbath, especially if that man or woman has not grown up in a Sabbath-keeping tradition. Sometimes people can lose their jobs for refusing to work on the Sabbath, and it takes faith to trust God to provide.
Here is an index to some recent posts in this blog about the Sabbath:
A Question and Answer about the New Covenant
Are the Ten Commandments Part of the New Covenant?
When Was the Sabbath Made?
The Ten Commandments, the Sabbath, and Animal Sacrifices