By what authority was Sunday Sabbath-keeping instituted?

Answer

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

Does it matter what one believes, so long as he is sincere?
What did those do who were baptized of John?
3. After the wise men had thus confessed their inability to do what the king required, who offered to interpret the dream?
What is said of the fourth kingdom?
What is necessary where there is a covenant?
What did the bishops determine to do?
How visible is His coming to be?

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