Well that is not true at all. Where does is say in the New Covenant God's Sabbath commandment is ABOLISHED and we are now commanded to keep Sunday Holy? Seems in your view Jesus and the Apostles wasted a lot of time teaching us about the Sabbath.
Who are God's Israel in your view? You do know the New Covenant is for the people of Israel right?
Jeremiah 31:33-34
33, But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people. 34, And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
Repeated in the New Testament.....
Hebrews 8:10-12
10, For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts:5 and I will be to them a God, and they shall be to me a people: 11, And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest. 12, For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more.
If you are not a part of God's Israel (not the nation) as defined in the Word of God the New Covenant is not for you....
Sunday Worship is a teaching and tradition that breaks the commandment of God. The Word of God says if you are following the traditions and teachings of man you are not following God and indeed not a part of God's Israel.....
Matthew 15:3-9
3, But he answered and said unto them, Why do ye also transgress the commandment of God by your tradition? 4, For God commanded, saying, Honor thy father and mother: and, He that curses father or mother, let him die the death. 5, But ye say, Whosoever shall say to his father or his mother, It is a gift, by whatsoever thou might be profited by me; 6, And honor not his father or his mother, he shall be free. Thus have ye made the commandment of God of none effect by your tradition. 7, Ye hypocrites, well did Esaias prophesy of you, saying, 8, This people draws nigh unto me with their mouth, and honors me with their lips; but their heart is far from me. 9, But in vain they do worship me, teaching for doctrines the commandments of men.
Who should we obey God or man?