Why is the Sabbath edict (Genesis 2 and Exodus 16) irrelevant in the New Covenant?

Because both the Genesis Sabbath and the Sabbath edict given Israel beginning in Exodus 16 foreshadowed the “rest” that Messiah would bring to humanity (Matthew 11:28) as He, alone, bridged the sin-chasm existing between humanity and the Father (1 Peter 1:18-19)…Jesus bridged that chasm through His faithfulness at Golgotha and the blood atonement He provided thereby making the imputation of His righteousness over our life possible by “faith” (2 Corinthians 5:21) thereby instituting the New Covenant promise of absolution from sin (Hebrews 8:12), eternally, for the one who believes Jesus is Messiah (John 3:16).

The Sabbath has been fulfilled in Jesus as all Law has been fulfilled in Jesus (Matthew 5:17) and we no longer walk by the letter in condemnation (Romans 8:1-4) but Christians walk by the Spirit in freedom (Romans 6:14; Galatians 5:16; Romans 7:6). We are no longer enslaved to Sinai, Moses, days, diets, fabrics, festivals, (Colossians 2:16; Romans 14; Hebrews 4) but we have peace with the Father through faith in the Son (Romans 5:1) as we walk in daily sanctification through the Holy Spirit who produces divine “fruit” through us that fulfills all Law and honors the Father, eternally (Galatians 5:16-23; John 15:8).

In closing,

You are free to honor the Sabbath or any day of your choosing in accordance with the Holy Spirit’s anointing in YOUR life but do NOT believe that your obedience to a day or a diet somehow enhances your salvation or your intimacy with our Creator, a salvation and divine intimacy that are the resultant of faith, not works (Galatians 2:16; Ephesians 2:8-9).