By what authority was Sunday Sabbath-keeping instituted?

Answer

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

What writings are specifically mentioned as containing some things difficult to understand?
What prophecy was fulfilled in the slaughter of the children of Bethlehem?
With whom are the children of God joint heirs?
What is the last book of the Bible called?
In view of the judgment, what exhortation is given?
What pitiful appeal did He make to the impenitent city?
In the new earth, what will he no more?

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