Sabbath day observance in our day is now more of a manifestation of individual devotion and commitment rather than a requirement of civil law.
Keeping the Sabbath day holy is much more than just physical rest. It involves spiritual renewal and worship. President Spencer W. Kimball gave excellent counsel on Sabbath day observance. He said:
"The Sabbath is a holy day in which to do worthy and holy things. Abstinence from work and recreation is important but insufficient. The Sabbath calls for constructive thoughts and acts, and if one merely lounges about doing nothing on the Sabbath, he is breaking it. To observe it, one will be on his knees in prayer, preparing lessons, studying the gospel, meditating, visiting the ill and distressed, sleeping, reading wholesome material, and attending all the meetings of that day to which he is expected. To fail to do these proper things is a transgression on the omission side." (The Miracle of Forgiveness, Salt Lake City: Bookcraft, 1969, pp. 96-97.)
I would counsel all students, if they can, to arrange their schedules so that they do not study on the Sabbath. If students and other seekers after truth will do this, their minds will be quickened and the infinite Spirit will lead them to the verities they wish to learn. This is because God has hallowed his day and blessed it as a perpetual covenant of faithfulness. (See Ex. 31:16.)
Why has God asked us to honor the Sabbath day? The reasons I think are at least threefold. The first has to do with the physical need for rest and renewing. Obviously God, who created us, would know more than we do of the limits of our physical and nervous energy and strength.
The second reason is, in my opinion, of far greater significance. It has to do with the need for regeneration and the strengthening of our spiritual being. God knows that, left completely to our own devices without regular reminders of our spiritual needs, many would degenerate into the preoccupation of satisfying earthly desires and appetites. This need for physical, mental, and spiritual regeneration is met in large measure by faithful observance of the Sabbath day.
The third reason may be the most important of the three. It has to do with obedience to commandments as an expression of our love for God. Blessed are those who need no reasons other than their love for the Savior to keep his commandments. The response of Adam to the angel who asked Adam why he made a sacrifice unto the Lord is a model for all. Responded Adam, "I know not, save the Lord commanded me." (Moses 5:6.)
In this day of increasing access to and preoccupation with materialism, there is a sure protection for ourselves and our children against the plagues of our day. The key to that sure protection surprisingly can be found in Sabbath observance: "And that thou mayest more fully keep thyself unspotted from the world, thou shalt go to the house of prayer and offer up thy sacraments upon my holy day." (D&C 59:9.)
Where is the line as to what is acceptable and unacceptable on the Sabbath? Within the guidelines, each of us must answer this question for ourselves. It is quite unlikely that there will be any serious violation of Sabbath worship if we come humbly before the Lord and offer him all our heart, our soul, and our mind. (See Matt. 22:37.)
What is worthy or unworthy on the Sabbath day will have to be judged by each of us by trying to be honest with the Lord. On the Sabbath day we should do what we have to do and what we ought to do in an attitude of worshipfulness and then limit our other activities.
James E. Faust: (excerpt from Ensign, November 1991, p. 33-35)