By what authority was Sunday Sabbath-keeping instituted?

Answer

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

Upon what conditions is an understanding of divine things promised ?
What are we exhorted by, the prophet to seek?
What is the whole world called upon to do?
Under the old covenant, what did the people promise?
7. What questions asked by its worshippers indicate the great station to which this beast-power was to attain?
How long will they live?
With what should our prayers be mingled?

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