Romans 12:2
And you people must not be conformed to [the values and standards of] this age, but you should become transformed [i.e., changed in attitude and action] by having your mind renewed [i.e., to think in a totally different way]. Then you will be able to determine [and practice] God's will, the thing that is good, and acceptable and perfect.
Ephesians 4:17
So, I tell you this, and insist [on it] by [the authority of] the Lord: Do not continue to live with worthless thoughts as [unconverted] Gentiles do.
1 Peter 4:3-4
For the time you have [already] spent in the past [i.e., as Gentile unbelievers] was long enough to have practiced unrestrained, indecent conduct, improper sexual cravings, riotous living, wild parties, drunken orgies and disgusting idol worship.