"For some days [Paul] was with the disciples at Damascus. And immediately he proclaimed Jesus in the synagogues, saying, 'He is the Son of God.' And all who heard him were amazed and said, 'Is not this the man who made havoc in Jerusalem of those who called upon this name? And has he not come here for this purpose, to bring them bound before the chief priests?' But Saul increased all the more in strength, and confounded the Jews who lived in Damascus by proving that Jesus was the Christ." —Acts 9:19-23, ESV
The beginning of Acts 9 shows Saul on his way to Damascus from Jerusalem to arrest Christians. Then he got knocked onto his tailend by Jesus. Then after Ananias came and shared with Paul God's plans for him. Paul believed and was baptized. From that moment on, Paul was unstoppable for Christ and his kingdom.
Here's the thing that hit me: Paul was changed. He was confronted and rocked by Jesus and he was CHANGED!!! And as I keep spending time in Scripture, the idea keeps popping out that life-change is proof that a person has truly met Christ. For someone to claim to have met Christ while seeing no life change proves that the initial meeting was not with Christ. Talk is cheap when a person's life shouts something completely different than his mouth.
If you claim you've met Christ but have not experienced any change, chances are that you didn't meet Jesus in the first place. I know we can claim that it's a process (and sanctification truly is a process), but conversion, being brought from death to life, happens at once. There is not a slow process of moving from death to life. It's in an instant. At one moment you're dead. The next: you're a live. The process of becoming healthier is truly that, a process, but the initial meeting should change everything.