Short Answer
I don't believe in the power of witchcraft. I believe in the power of people. People can manifest energy (good or bad). Some do it via witchcraft. Others do it via prayer. Others do it with meditation. The medium doesn't matter. It's all about the mind and focusing one's intentions.

Long Answer
I was a witch for more than a decade. Probably closer to two. I was attracted to it in junior high, quite possibly because it did have mysterious qualities and I fancied myself as a bit of a rebel at the time. Back then, I was all into the idea of spellcasting. I remember my BFF and I would do all sorts of oddball things, like spells to have good luck during tests and to heal wounds. We also did protection spells to stop people from bullying us, but it was all very childlike, really. And, it was all very pure.  

By the time I hit my late teens, I became more interested in the actual religious roots of what I was doing. Then, I started studying paganism and Wicca. I became a very active solo practitioner, observing the holidays and having full moon rituals. I found it much easier to believe in multiple gods and goddesses than to believe in a singular omnipotent god. Multiple gods with dueling agendas could explain the state of the world to me in a way I could relate. 

Totally by chance, I started dating a guy and realized AFTER we were dating that he was also a witch. I ultimately ended up marrying him and a huge part of that was because we shared the same religion. Male witches are somewhat of a rarity to begin with and I only personally know two who are straight. lol 

He and I often did our full moon rituals and such together. I raised my oldest son as a witch. He's agnostic now. Anyway, we did family rituals and stuff. We did a family trip to Salem as well. I was never ever into the darker side, but my ex was. I was part of a coven for a while and even became a high priestess as well as an ordained minister. I was very much a traditionalist. I followed the rule of three, which essentially states that anything you do will come back to you threefold. If you do bad things, expect bad things to happen to you. I also followed the Wiccan Rede: "An' ye harm none, do what ye will." This was more or less my guide for everything back then and it still is. I was performing handfasting ceremonies (weddings) for the LGBT community way way way before that was even a thing. We're talking like as early as the early 2000s. (Ok, the LGBT community was always a thing, but performing handfasting ceremonies at a time when everyone was still closeted in an era of "don't ask, don't tell" was fairly progressive.)

I don't remember when my personal shift happened. Maybe my late 20s or early 30s... anyway, at some point, I realized I didn't believe in most of what I was doing. Some of that might have been similar to what Sharonna experienced. Being part of a coven has its drawbacks. Nobody in my group was dark that I'm aware of, but some of them believed in faeries and such, to the point they'd leave them snacks and worship them too. That caused me to pull away from the group. It was all too crazy for me. And, then, little by little, I let go of most of the pagan beliefs I had. 

It kind of left me as a bit of a unique duck, spiritually speaking. I saw the power of what could happen when magik was afoot, especially in groups, but I attribute it to the individuals involved, not any kind of god or goddess. I think humans are remarkable beings with amazing capabilities, whether that manifests itself in the power of prayer or a ritual circle. It's not about the religion or even the rituals performed. It's more about willing things to happen. Building positivity around you and living with intention. Acting with intention. It can be likened to believing in yourself. And this, I could actually back up with tons of scientific studies, but when people believe they can do things, be it generate cash or score well on a test, they usually do. When people have biases against themselves and negative thought processes, they can't succeed. The human mind is incredible. I'm not sure where I sit on the topic of manifestation because I have seen that work too-- in ways that cannot be explained by science-- when the person trying to manifest something has no control over the outcome. Is it luck? Is it positive energy? I don't know. But, I also think there's something to that as well and I don't believe it's unique to Wicca.