By what authority was Sunday Sabbath-keeping instituted?

Answer

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

What are some of the attributes of God?
Into whose name are believers to be baptized?
After bringing Him to the place of crucifixion, what drink was offered Christ to stupefy Him?
What, more than all else, proves the perpetuity and immutability of the law of God?
6. What occurred at the time of the crucifixion which indicated that the typical system had been taken away by Christ?
Why does the Lord call the Sabbath His day?
By what title is the first state of the church distinguished?

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