"I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain." Galatians 2:21 ! You call yourself a Christian or a Messianic Jew? That is great! But you need to make up your mind about whether to stay under the law or to be under grace. I hope you will take time enough to read the following... Your eternal life is in danger if you still want to keep the Sabbath...
Paul was a Jew, and He wrote:
"But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? Ye observe days, and months, and times, and years. I am afraid of you, lest I have bestowed upon you labour in vain." Galatians 4:9-11 KJV
Also, Jesus rose from the dead on a SUNDAY, and that is why I also worship Him on Sunday. Jesus is LORD over the Sabbath and eben healed on a Sabbath. Whoever wants to keep the Sabbath or the law will be judged by the Sabbath or the law.
The Apostle Paul also said:
"Christ is become of no effect unto you, whosoever of you are justified by the law; ye are fallen from grace. For we through the Spirit wait for the hope of righteousness by faith. For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love. Ye did run well; who did hinder you that ye should not obey the truth?" Galatians 5:4-7 KJV
And another reason to worship on Sundays is in the Psalms...
"For the LORD God is a sun and shield: the LORD will give grace and glory: no good thing will he withhold from them that walk uprightly." Psalms 84:11
And if you do not believe it by now, take this example by the Apostles, the early church, and read that they also met on Sundays (the first day of the week) for the Supper of the Lord:
"And upon the first day of the week, when the disciples came together to break bread, Paul preached unto them, ready to depart on the morrow; and continued his speech until midnight." Acts 20:7 KJV
But the very best proof is this:
"Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days: Which are a shadow of things to come; but the body is of Christ." Colossians 2:16
So, take it to heart, repent and get away from the Sabbath, or you will be as lost as a goose. I would love to see you in Heaven one day!
"Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin." Romans 3:20 KJV
"Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God. Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin. But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets; Even the righteousness of God which is by faith of Jesus Christ unto all and upon all them that believe: for there is no difference: For all have sinned, and come short of the glory of God; Being justified freely by his grace through the redemption that is in Christ Jesus: Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God; To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus. Where is boasting then? It is excluded. By what law? of works? Nay: but by the law of faith. Therefore we conclude that a man is justified by faith without the deeds of the law." Romans 19-28
"I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain." Galatians 2:21
"For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death. But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter." Römer 7:5-6 KJV
Wishing you great day of the LORD today, a Sunday, hope you read the New Testament also in the future and convert to Christianity by getting away from the old law. It is necessary! Go for it!
Love in Christ, Vera