By what authority was Sunday Sabbath-keeping instituted?

Answer

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

How does godly sorrow for sin manifest itself?
How has Christ made it possible for righteousness to be imputed to the believer?
By what is this cleansing from sin and fitting for God's service accomplished?
Why was it necessary for Christ to go away?
Where will Christ then take His people?
After resting on the seventh day, what did God do?
7. Seeing, then, that the Sabbath is holy, is to be kept holy, and is a day for holy convocations, what must be its character?

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