Deism is a belief that there is a God who has created the universe, but remains apart from it and therefore we don't have any revelations. This worldview begs the question that if there are no revelations from this God and this God stays apart from creation, then how on earth can we know anything about this God? The main problem with Deism is very much like the problem with Atheism; whether you're willing to acknowledge the fact that there is a God or not, you can't claim to know if this God is guiding you or deceiving you or is just experimenting something and you're part of the experiment, and as long as you can't answer this question, you can't claim to know anything to any degree, because you don't have any evidence or records of this God in human history whatsoever, in order to appeal to and make a case for why we should trust our cognitive faculties that are created by this anonymous God. But the Christian God is a personal God and He has spoken and revealed Himself to us, not only through His Creation, consciousness and conscience, but also most specifically through the Scriptures, or the Bible, written throughout the human history.
Most of the deists that I know are agnostic; in other words, they're not making any knowledge claims about this God that they're appealing to and are open to the truth of the Gospel, in which case witnessing or arguing takes a different path and the historical evidence for resurrection would be a good start. On the other hand, there are deists who are hard-core, and anti-theist; they actually claim that all religions are false, and they try to justify their ability to reason by appealing to an anonymous God; but as I said above, this will beg the question as to on what basis they are trusting something that has been designed by an anonymous God whom we have no idea what is up to? Now the objection that they might have to us questioning their blind faith will go something like this, “The same thing applies to everyone, or any theist. You too, can't know if the God of Bible is deceiving you or not.” This is the tu-quoque fallacy, and by committing this fallacy, not only do they refute themselves by undermining their trust in their cognitive faculties, and then generalizing it by making a truth claim about everyone else, but also they are wrong about the Christian worldview. Because according to the Christian worldview, as I explained above, the Creator of the universe is a personal God, and He has revealed the truth to us such that we're without excuse. That's how we can be absolutely certain that child molestation is immoral, and it would be ludicrous to say that there might be a god or a supernatural power who is deceiving us about this issue, and child molestation could be moral! Not only that, but the Christian God has been present from the beginning of Creation, and has warned His Creation from the very beginning about what would happen if they disobey Him. The book of Genesis is one of the reasons that Bible stands out.
Now if they want to appeal to a personal God which is what Pantheists usually do, then they're going to have to need an objective source of divine revelation to justify what they're saying, which is something that both Deists and Pantheists are afraid of. The main reason Deists don't like to affiliate themselves with any religion, is because they don't like to appeal to divine revelations or a book so as to speak. If they want to claim that the only divine revelation that they're appealing to is through our consciousness and conscience which is what Pantheists do, then we can press them on more difficult moral issues such as same-sex relationships or incest for instance, and they need to demonstrate how we can tell who's got the right revelation from God? Them or those who disagree with them? The point is to demonstrate that without a written revelation, we can't have an objective source and everyone can claim to have a divine revelation everyday and we won't have a way of telling who's telling the truth. Now they might say that written revelations are also subjective and open to interpretation because they're written by men, and that's correct which is why we expect a rational God to reveal the written revelations throughout the history within different generations, with prophecies and signs, and make it stand out among all the other counterfeits, and if you look into the history, there's only one revelation like that, which is the Bible and this is the very reason why Bible is still the best-seller in the world, except of course the countries that have banned it and resort to censorship in order to make indoctrination easier.
If you haven't read my article on debunking atheism, I strongly recommend that you read it. If you learn how to debunk atheism, then you can use the same arguments in order to debunk almost any worldview, especially those that do not appeal to properly preserved and reliable divine revelation from God throughout human history which is pretty much every single non-Abrahamic worldview that is out there! The only worldviews that appeal to infallible divine revelations from God throughout the human history are the Abrahamic worldviews and among them, Christianity stands out, mainly because of having more than 300 prophecies fulfilled in the New Testament and the resurrection case. I also explained in another article why Islam cannot be true, and I am planning to write articles on debunking the other cults that exist within the Abrahamic worldview, plus the Jewish objections to Jesus. I believe the articles that I have written on debunking Islam, Atheism and Deism so far, are enough to debunk all non-Abrahamic worldviews plus Islam which is an Abrahamic worldview that appears to be the closest one to Christianity, but it's just a counterfeit and it's easy to debunk it. Also, the same reasoning that I have used in this article can be used to debunk ridiculous analogies such as why not Magical Pixies, Santa, Zeus, etc.
