The seventh day, the Sabbath, means one day before God. Keep it up one day as God’s day. But according to the New Testament, every day is God’s day. Not a single commandment has changed. Jesus fulfilled every command. According to the New Testament, not just a day, but every day is a holy day.
It is the same thing as observing the Sabbath and always be ready. In the Law, the Sabbath was just a day. But always be prepared in the New Testament. You are not told to observe one day only. At the same time, it is prepared, not by ritual, but by the purity of the Spirit.