By what authority was Sunday Sabbath-keeping instituted?

Answer

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

How has God revealed to us the hidden things of the kingdom?
By what means is all Scripture given?
Of what sanctuary, or tabernacle is Christ the minister?
Who is this dragon?
What directions were given by Constantine's Sunday law of March 7, 321?
What is said of the strength and character of the angels?
How many foundations has this city?

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