The purpose of Sabbath is not ...

The purpose of Sabbath is not simply to rejuvenate yourself in order to do more production, nor is it the pursuit of pleasure. The purpose of Sabbath is to enjoy your God, life in general, what you have accomplished in the world through his help, and the freedom you have in the gospel-the freedom from slavery to any material object or human expectation. The Sabbath is a sign of the hope that we have in the world to come.
The purpose of Sabbath is not simply to rejuvenate yourself in order to do more production, nor is it the pursuit of pleasure. The purpose of Sabbath is to enjoy your God, life in general, what you have accomplished in the world through his help, and the freedom you have in the gospel-the freedom from slavery to any material object or human expectation. The Sabbath is a sign of the hope that we have in the world to come.

Quotes from the same author

Gifts are abilities God gives us to meet the needs of others in Christ’s name.
The main human problems often are that we misidentify what will make us happy; and we ask people and things to save us beyond their ability.
Our moral efforts are too feeble and falsely motivated to ever merit salvation.
Without the gospel we hate ourselves instead of our sin. Without the gospel we’re motivated through all sorts of awful fear and pride to change and it doesn’t really change our hearts; it just restrains our hearts.
Faith in the gospel restructures our motivations, our self-understanding, our identity, and our view of the world. Behavioral compliance to rules without heart-change will be superficial and fleeting… We can only change permanently as we take the gospel more deeply into our understanding and into our hearts. We must feed on the gospel, as it were, digesting it and making it part of ourselves. That is how we grow.