For if thou wast cut out of that which was by nature a wild olive tree ( ἀγριελαίου), and wast grafted contrary to nature into a good olive tree ( καλλιελαίου): how much rather shall these, which be branches by nature, be grafted into their own olive tree?
In what follows next the eventual coming of the Jewish nation into the Church is not only anticipated as possible or probable, but foretold prophetically. St. Paul announces it as a "mystery," which his readers may be ignorant of, but which he wishes them to know.
By the word μυστήριον, as used by St. Paul, is meant something hidden from man in the Divine counsels till made known by revelation (see 1 Corinthians 2:7, 1 Corinthians 2:10; 1 Corinthians 15:51; and, in this Epistle, Romans 16:25, Romans 16:26—a passage which expresses clearly the apostle's meaning in his use of the word).
In the LXX. it denotes any Divine secret, which may or may not be made known to man (cf. Daniel 2:18, Daniel 2:19, etc.; Job 11:6; Wis. 2:22; Ecclesiasticus 22:22; 27:16). So also in the Gospels it is said to be given to the disciples to know the mysteries of the kingdom of heaven, but to others in parables.
In classical Greek μυστήρια were Divine secrets (as in the Eleusinian Mysteries) which were revealed to the initiated alone. St. Paul uses the word with the same essential meaning; only he speaks of mysteries which had already been revealed to himself and others by the Spirit, and has ever in view the Divine purposes, previously unknown, for the salvation of mankind.
Thus in Ephesians 1:9, seq.; and Ephesians 3:3, seq., he speaks of the Divine purpose to "gather in one all things in Christ," and that "the Gentiles should be fellow-heirs," etc., as a mystery, "not made known in other ages unto the sons of men," but now revealed to the "holy apostles and prophets by the Spirit."
(The other passages in which St. Paul uses the word are 1 Corinthians 4:1; 1 Corinthians 13:2; Ephesians 5:32; Ephesians 6:19; Colossians 1:26, Colossians 1:27; Colossians 2:2; Colossians 4:3; 1 Timothy 3:9, 1 Timothy 3:16; 2 Thessalonians 2:7.
) Here he announces the Divine purpose to save "all Israel" at last through the calling of the Gentiles as a mystery which has been revealed to himself and others, and which he desires the Gentile Christians to be aware of, lest they should be "wise in their own conceits," i.
e. presume on their present position of privilege through ignorance of what is in store for Israel.