Why is resting in Christ significant for believers?

Resting in Christ means trusting in the sufficiency of His sacrifice and obedience. As stated in Mark 2:28, Christ is the Lord of the Sabbath, and He provides the rest that the law could not give. The law serves to point out our inability to achieve righteousness on our own, thereby directing us to rely solely on Christ for our salvation. This rest allows believers to stop striving for justification through their own efforts and instead accept the grace offered through faith in Jesus, who has fulfilled the law on our behalf.