According to the apostle John, you can be sure of this: only those who hunger and thirst for righteousness are Christians; and those who do not, are not Christians. A person reveals the kingdom they belong to by the things that they crave and feed on. Our appetites are driven by the desires of our hearts. Before we were born again, Paul writes that we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind, and were by nature the children of wrath, even as others (Eph 2.3).
After our new birth, we still retain our sinful flesh, but as we will see, our desires change. We now crave intimacy with Jesus and the things that will build us up in our relationship with Him. Once we come to Christ we are filled, but because the greatness and pleasures of God are more than can be imagined, we still hunger for more of Jesus and those things that feed that new man in Christ.
What a person feeds on or craves will shape the course of their life and worldview. I know of nothing that will more affect your total worldview and behavior than the unflagging desire to be holy like Jesus Christ. Let me ask you (and myself) a few pointed questions. Do you desire to be like Christ? Does this burn in your heart? Does it affect the decisions you make, the relationships you enter, the way you use your resources, the way you use your time, the things you do for recreation, the way you approach your education and vocation? What you hunger for will either bless you or destroy you. Selah