By what authority was Sunday Sabbath-keeping instituted?

Answer

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

In view of God's great love to us, what ought we to do?
Does faith exclude works?
Because some thought He had come to destroy the law, what did Christ say?
What is said of those who love God's law?
Where was the law of God written under the old covenant?
What is the first which He took away?
What pitiful appeal did He make to the impenitent city?

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