For what purpose is the mystery of the gospel made manifest?

Answer

But now [the mystery] is made manifest, and by the Scriptures of the prophets, according to the
commandment of the everlasting God, made known to all nations for the obedience of faith." Rom. 16: 26.

Was Satan created sinful?
With whom are the children of God joint heirs?
How many are sinners?
What is said of the poor but wise child?
What proposition did He submit to them?
Who made the Sabbath?
To whose authority are the angels subject?

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