The latter half of Chapter 4 of Paul's letter to the Ephesians is the watershed of this magnificent document that is often referred to as the holy of holies. Paul was never hesitant to declare God's truth as he proclaimed it to those professing faith in the Lord Jesus Christ. Therefore, after praising The Triune God for the love, wisdom, and blessings bestowed upon us during the first three and one-half chapters Paul does an about face and enjoins the believers with these strong words saying, This I . . . testify in the Lord, that ye henceforth walk not as other Gentiles walk in the vanity (futility) of their mind. He is telling the hearers that once they are Christ's they are to walk to a different drummer, the Master Himself.
Paul completes the watershed transition by reminding professing Christians, But ye have not so learned Christ. It is with these simple, single syllable words that he opens new horizons for the members of Christ's body and paves the way for enunciating the duties and responsibilities they are to learn and to do when Following Christ. This learning and practicing is not easy, but it us joyful, rewarding, and worthwhile.
That is why Paul, before embarking on Christ's learning pathway, tells the followers in the way to, put off . . . the old man; be renewed in the spirit of your mind; And . . . put on the new man, which after God is created in righteousness and true holiness. May we heed God's truth as revealed to Paul by the Holy Spirit. These blessings are comforting, strengthening, and manifold when committing ourselves to Walking With Jesus.