“Now to him who is able to strengthen you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery that was kept secret for long ages but has now been disclosed and through the prophetic writings has been made known to all nations, according to the command of the eternal God, to bring about the obedience of faith— to the only wise God be glory forevermore through Jesus Christ! Amen.” (Romans 16:25-27)
As Paul draws his letter to the Romans to a close he expresses a theological truth with great emotion. The truth is a wondrous mystery that was long spoken of by the prophets has been revealed. That mystery has two parts to it. The first is the Incarnation. Almighty God’s plan was to send a Messiah, a Savior to reconcile the world unto Himself, to free the world of sin and death. But how exactly that Messiah would do it was not clear to the Jews even though the prophets had written of it. By the time of Jesus, the religious rulers of Israel interpreted this as a temporal or earthly Messiah. To them the Messiah would overthrow the Roman oppressors by military might and reestablish the great Kingdom of David.
The second part of that mystery is that the Kingdom of God is no longer of a temporal Kingdom nor is it composed merely of Jews. The Kingdom of God is now the Church of Jesus Christ. The Church is open to all men and women of all ethnicities, languages, races, nationalities and socio-economic groups including slaves. Such was the very makeup of the church at Rome. The great mystery is that God works through Jesus Christ to establish His will and His rule and He works through the Church to do the same through the empowering ministry of the Holy Spirit.