By what authority was Sunday Sabbath-keeping instituted?

Answer

By the authority of the Catholic Church. See page 131.

With whom are the children of God joint heirs?
What is the beginning of wisdom?
How should all Christian parents bring up their children?
If John, therefore, referred to a day of the week, on what day must he have been in the Spirit?
What directions were given by Constantine's Sunday law of March 7, 321?
What pitiful appeal did He make to the impenitent city?
What protection has God promised His people during the seven last plagues?

Questions & Answers are from the book Bible Readings for the Home Circle