All of the words God gave through the Bible for our salvation are important. We should not add my thoughts to the Bible, nor subtract the words. The Early church observed the Sabbath and Passover, never observed Sunday services and Christmas. That's because there was no Sunday and Christmas in God's Word. God recorded the Bible so that we could receive forgiveness and enter heaven. So he repeatedly emphasized, "Don't add or subtract anything from the words of the Bible.
The Church of God keeps the Sabbath and Passover as the Bible says, and believes in God the Father and God the Mother. The Church of God is the only church on earth that believes and practices as the Bible says.

I warn everyone who hears the words of the prophecy of this book: If anyone adds anything to them, God will add to him the plagues described in this book. And if anyone takes words away from this book of prophecy, God will take away from him his share in the tree of life and in the holy city, which are described in this book. (Rev22:18-19)