To rest is to cease from work. This work is either physical or spiritual. The law was concerned with the physical but the new covenant is concerned with the spiritual. The law was only a shadow but Christ is the light. The physical is a shadow of the spiritual. The sabbath of the law foreshadows the sabbath of the new covenant of Christ. Christians rest from performing the physical works or rituals of the law, their sabbath is Christ from works that only lead to death. Rather than work yourself to death let God work in you and you sabbath or rest. We are Gods workmanship, we do not work. This is the sabbath that remains in Christ. Matthew 11:28-29 The verse faith without works is dead refers to the works of God in you not the works of the law. James 2:26 If you are Gods work, primarily love, then these works should be evident.