By what authority was Sunday Sabbath-keeping instituted?

Answer

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

What is the result of faith's being put to the test?
When may we find acceptance with God through Christ?
How is sin defined?
By what law is the knowledge of sin?
What further imperial legislation in behalf of Sunday observance was issued in 386?
What title is given the last book of the Bible?
How are God's remnant people described?

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