A genuine Christian WILL undergo a Transformation unless they are granted Eternal Life just prior to death. But if a person has been alive for a significant period of time, a change of thinking will be evident. Mostly, though, it will be evident to the individual more than anyone else. When a person has been lifted of the Curse of the Lord, their entire way of thinking changes from possessing the Mind of the Devil to the Mind of Christ. Think of the change of thought that Adam and Eve had as they went from perfect thinking to corrupt thinking. A True Christian will experience that same change but in reverse. We will change from evil thinking to Righteous and Holy thinking.
Ezekiel 36:25-27 NLT - 25 "Then I will sprinkle clean water on you, and you will be clean. Your filth will be washed away, and you will no longer worship idols. 26 And I will give you a new heart, and I will put a new spirit in you. I will take out your stony, stubborn heart and give you a tender, responsive heart. 27 And I will put my Spirit in you so that you will follow my decrees and be careful to obey my regulations."
The above is what happened to our Father of Faith, Abraham, and this is the same Promise that is granted to all who are the Lord's Holy Elect.
Romans 2:27-29 NLT - "In fact, uncircumcised Gentiles who keep God's law will condemn you Jews who are circumcised and possess God's law but don't obey it. 28 For you are not a true Jew just because you were born of Jewish parents or because you have gone through the ceremony of circumcision. 29 No, a true Jew is one whose heart is right with God. And true circumcision is not merely obeying the letter of the law; rather, it is a change of heart produced by God's Spirit. And a person with a changed heart seeks praise from God, not from people."
This same Faith is given to all, even the Gentiles. It is the SAME Faith.