After dialoging with several Wiccans and reading countless pages from Wiccan authors concerning their various traditions, I have come to the conclusion that Wicca is not falsifiable. In other words, Wicca cannot be proven to be false -- or true. Falsifiability is an important part of evidence and even of belief. Let me explain.
Years ago in San Diego there was a UFO cult called Heaven's Gate. About 40 members simultaneously committed suicide. They believed that on the other side of the approaching Hale-Bopp comet was a UFO. The members of this cult believed that if they were to die in a simultaneous manner coordinated with the arrival of that comet, their souls would be delivered from this earth plane by the aliens in that space ship. Now, how do you prove their belief false? Can you go to the other side of the comet and see if there's a UFO there or not? No, you can't. This means you cannot prove their belief system to be false because there is no method of verifying their theological position. This is very important because the implication is that their theology does not rest in reality.
If I were to make up a theological system and try to get converts, I would not want my system to be able to be proven to be false. Therefore, I would need to arrange a theology in such a way that it cannot be disproved. I would avoid stating that a certain event happened at a certain place and time because that could be verified. I would make up a system that is vague and has no ties to anything that can be checked out. It could not be proven to be false and I would be free to get all the converts I could muster.
Wicca is like that. It cannot be proven to be false because there is nothing in it that can be examined so as to demonstrate that it is true or false. But, Wiccans may say that it can be shown to be true because their spells and incantations bring results. But the problem with that explanation is that other reasons can be given to account for these so-called results. For example, the spell or incantation could be coincidental with the result. It could be that there are demonic forces behind these occult practices and these demonic forces bring the results so as to deceive the Wiccans. It could be that the Wiccans are misinterpreting what they see as results in a hopeful self-fulfilling type manner, etc. But various possible explanations cannot be verified within Wicca because, basically, Wicca is a subjective belief system based upon occult practices that have varying degrees of alleged results which could be explained in several different ways. Therefore, it is not falsifiable and the implication is that it does not rest in reality in that it has no event, objective truth, etc. that can be verified. Wiccans believe it because they want to.
Christianity is falsifiable
Christianity on the other hand is falsifiable. It can be proven to be false if, for example, the body of Christ was discovered and it was conclusively demonstrated that it was his body. If such an event occurred, that it would mean that Christianity is false because Christianity is based on the physical resurrection of Christ. The reason Christianity is falsifiable is because it rests in history. In other words, there were actual events that can be verified and the basis of Christianity, the resurrection, can be undone if the body of Christ can be discovered archaeologically. The point is that Christianity rests in reality, not in unverifiable theory--and that is hugely important.
The difference between Christianity and Wicca is that Christianity is based upon an actual person in history who performed many miraculous deeds in front of eyewitnesses, died, was buried, and rose from the dead. Christianity is based upon an event in history. Wicca, on the other hand, is not. It is based on subjective experiences and contact with powers that no one knows for sure what they are. Simply believing that these results come from spells and incantations from being in tune with nature and the God and Goddess, does not mean that those results are good or that Wicca is right. Someone could just as easily state that the results come about because the witch is breathing properly and the breath harmonizes with the "universal life cycle." How would you know which is true and which isn't? You wouldn't.
Wiccans are definitely in contact with something and their theological system is arranged in such a way that its underlying theological premises cannot be verified or shown to be good or bad. And this, of course, is dangerous.
But, the Bible says
But the Bible says that the source of the results wrought from spells and incantations is ultimately demonic. Is the Bible correct or not? Well, that is another discussion. But, the Bible is full of verifiable places and events as well as eyewitness' accounts of the miraculous. Which would you want to put your trust in, a risen Messiah who performed numerous miracles or the worship of gods and goddesses where you cast spells and summon the forces of who-knows-what in order to manipulate people and/or things to get what you want? For me, I'll trust Jesus over spells and magic.