Sunday worship and the Sabbath; the SDA cult!

What does the Seventh Day Adventist (SDA) religious movement believe about Sunday worship and the Sabbath?
“And he said unto them, The sabbath was made for man, and not man for the sabbath:
Therefore the Son of man is Lord also of the sabbath.” (Mark 2:27 to 28)
https://www.azquotes.com/quote/313124?ref=commandments-of-god
https://adventist.org/identity/history/ellen-white/great-controversy-book
https://sealedbytheking.com/
https://www.e-sword.net/
https://www.purebiblesearch.com/
https://www.jw.org/en/library/bible/study-bible/books/
https://www.azquotes.com/quote/856730
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