I have met several young adults who became witches as an act of rebellion against Christianity. I am not one of them. In fact, I would have become a pagan years earlier if it hadn't met so many pagans who hated Christianity. I have no interest in a religion that exists primarily as a negation of another.
I didn't rebel against Christianity. I discovered paganism as a wholesome religion, on its own terms. The draw to paganism has been a part of my life as long as I can remember. I used to interpret it as a calling to bring Christ to the pagans, i.e. the light to the darkness. But looking back now I know that the richness of mythology and the magic of nature has always beckoned to my spirit.