In Paul's letter to the Ephesians, he writes to the believers, "Now I say this and testify in the Lord, that you must no longer walk as the Gentiles do" (Ephesians 4:17). Paul uses "Gentiles" in the context of this sentence to refer not to their ethnicity, but to their spiritual condition & identity that is "outside" of Christ; they are non-believers.
Paul is making the declaration: there is a distinctness to the lifestyle of a believer that is noticeably different from that of a non-believer. However, apparently, some in the congregation at Ephesus didn't get the memo. So, Paul is telling them to "stop living according to the rhythm of the world". There is a rhythm to everyone's life. For the believer, we are to be living according to the rhythm of Christ, living according to our new identity in him...that is, distinct, different, set apart in "true righteousness and holiness" progressing ever more closely to the character of Christ as we "put off" the old man, are "renewed in the spirit of our minds", and "put on" the new man. This includes our attitudes, actions, worldview, behaviors, and ambitions.
There is a country song out now, a duet with Carrie Underwood and Sam Hunt. Part of it says, "dancing to the rhythm of your heartbeat". I wonder today, Christian, are you dancing to the rhythm of the heartbeat of the world or to the heartbeat of the gospel and the kingdom of Jesus?