Romans 12:2 (NKJV)
“and do not be conformed to this world, but be transformed by the renewing of your mind so that you may prove what is the good acceptable and perfect will of God.“
Christianity is all about being transformed from the inside out by believing in Jesus Christ and living in the Holy Spirit. It is about coming out of the darkness and into the light. It is about going from being dead to fully alive for real. It is about going from being an enemy of God to a friend of God. It is about going from being a child of the devil to a child of God. All of which can only be achieved in Jesus Christ (John 14:6). It is not merely a life of behavioral modification, but of inner transformation through being renewed (Ephesians 4:23-24).
Jesus told an old religious ruler who knew all of the law of God and was a teacher of the law, that he must be born from above (or again) or he will not see the kingdom of God (John 3:3). Most religions of the world emphasize that it is the outward living that matters; however, Jesus emphasized that it is the inward transformation that leads to outward living that pleases God (Matthew 23:25-26).
So, the question is, “How does one become transformed?” Well, the answer is simple, yet costly, but so worth it. First, your reasonable service to God is to offer up yourself as a living sacrifice in such a holy way that it is acceptable to Him (Romans 12:1). Then, to stop allowing the world to influence you, (reject the worldly mentality and ideas that have been dictating you on how you should live), but instead, be transformed by the renewing of your mind (Romans 12:2).
The most honest and best question I can give you in how to renew your mind is to start a daily habit of studying the Bible (2 Timothy 2:15). Invite the Holy Spirit to teach you. We cannot live the transformed life without the Holy Spirit. He is the One who transforms us (2 Corinthians 3:18).