The Bible says that becoming a follower of Christ is like a dead person coming to life. Moving from spiritual death to spiritual life is a drastic change. Spiritual rebirth makes it possible for us to consciously share God’s love and partner with Him in bringing about his kingdom. Although spiritual rebirth brings instant change, it doesn’t result in an immediate transformation. We are too deeply flawed for an instant cure. When we choose to follow Christ, a process begins that will continue to the end of our lives.
Before we followed Christ we were, in a sense, like zombies—spiritually dead and driven by urges and emotions we didn’t understand. Even after we were awakened by spiritual life the same urges and emotions remained, although we were no longer entirely under their control (Galatians 5:17–21; 6:8; Ephesians 2:2–6). The New Testament uses a special term to refer to these urges and emotions: the “sinful nature.” 
Our natural inclination to sin continues to generate impure thoughts that are out of sorts with our new life. But these bad thoughts don’t represent our current spiritual state. They represent the death we are leaving behind.
In addition to our own natural faults and weaknesses, Satan acts as an adversary (see Job 1:7–12), “slanderer,” and “accuser” (Revelation 12:10). He wants us to be obsessed with our dark thoughts. If we do, he—like a vampire—can drain away our joy and the influence of our new life.
Since we will never be completely free of lustful, unkind, and self-destructive desires in this life, we need to have realistic expectations. Experiencing a bad thought isn’t the same as hanging on to and nurturing it. Our goal shouldn’t be to eliminate bad thoughts but to be quicker to recognize and resist them when they appear. Far from indicating that our faith isn’t real, our awareness of continuing impure thoughts and unfree tendencies that still lurk within us proves that we are being transformed. If we weren’t becoming more spiritually aware, we wouldn’t even recognize the lingering shadows of spiritual death. First John 1:8 says, “If we claim we have no sin, we are only fooling ourselves and not living in the truth,” and the apostle Paul describes his continuing struggle with sin (Romans 7:15–25).
In fact, it is important that we recognize the wrong within. If we didn’t recognize the impurity that still remained in us, we might be drawn into the most dangerous sin of all—spiritual pride.
 John 5:21; Romans 6:13; 8:11; Ephesians 2:1–3; 5:14; Colossians 2:13
 In the New Testament the Greek term, sarx, often translated “flesh,” occasionally refers to the body, but most often refers to the destructive, death-prone tendencies within us. These tendencies still reside in us even after conversion, while we are moving from spiritual death to spiritual life. Paul calls it the “law of sin at work within me” in Romans 7:23 (niv). The Bible calls this the “sinful nature” in Romans 7:18 and 7:25.
 The name “devil” is from the Greek word diabolos, meaning “slanderer, false accuser.”