Verse 4. - In accordance with which, when ye read, ye may understand my knowledge in the mystery of Christ. Προσ ο}, with reference to which, i.e. to what I wrote afore: to make that more intelligible I write on the subject more fully now, so that you shall see that your instructor is thoroughly informed in this matter of the mystery in Christ - this once concealed but now revealed purpose of his grace.

3:1-7 For having preached the doctrine of truth, the apostle was a prisoner, but a prisoner of Jesus Christ; the object of special protection and care, while thus suffering for him. All the gracious offers of the gospel, and the joyful tidings it contains, come from the rich grace of God; it is the great means by which the Spirit works grace in the souls of men. The mystery, is that secret, hidden purpose of salvation through Christ. This was not so fully and clearly shown in the ages before Christ, as unto the prophets of the New Testament. This was the great truth made known to the apostle, that God would call the Gentiles to salvation by faith in Christ. An effectual working of Divine power attends the gifts of Divine grace. As God appointed Paul to the office, so he qualified him for it.Whereby when ye read,.... The above chapters, and seriously consider what is contained in them:

ye may understand my knowledge in the mystery of Christ of his person, office, and grace; and which knowledge was very large indeed.