In Colossians chapter 3 verse 5, it says; "Therefore put to death your members which are on the earth: fornication, uncleanness, passion, evil desire, and covetousness, which is idolatry." Why does the New King James Version use passion I was under the impression that passion is a good thing.

       The verse you mention that is in the book of Colossians uses the word 'Passion' in several versions of the bible such as the New King James version (NKJV), the English Standard Version (ESV), the New American Standard Bible (NASB) and the American standard Bible (ASB) to name a few. The King James version (KJV) uses the terms 'inordinate affection'. Either way, the original Greek word is "Páthos" which is derived from another word that means a type of suffering. Suffering in a sense that the body has a willingness to want to do evil. So it is defined in this context to have a lustful desire or wrong kind of 'passion' for someone or something. The verse in its entirety is;

“Therefore put to death your members which are on the earth: fornication, uncleanness, passion, evil desire, and covetousness, which is idolatry." Col. 3:5 (NKJV)

                                                                                                      or;

       "Mortify therefore your members which are upon the earth; fornication, uncleanness,  nordinate affection, evil concupiscence,

         and covetousness, which is idolatry:" Col. 3:5  (KJV)

          Both versions give the same meaning which is that we are to give up the ungodly life of this world and it's evil, unclean actions and wrongful desires (Passion) which is what it means to 'put to death' those things that prevent us from living a proper life in Christ.

          In the beginning of the verse where it says; "put to death your members", the word members is translated from the Greek word Mélos  and refers to a part or member of the body. In other words put to death, those things in you, or your mind that have to do with these sins.