By what authority was Sunday Sabbath-keeping instituted?

Answer

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

What is said of God's faithfulness in keeping His promises ?
Can anything separate the true child of God from the love of God?
What gracious promise does God make to His people?
How faithfully should parents teach their children the Word of God?
By what is the knowledge of sin?
Does the Bible recognize this as the proper time for beginning and ending the Sabbath?
What courage and strength, therefore, should come to us even in the hour of affliction?

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