If you are Jehovah’s Witness please watch this.
There are many good sites for Christian Apologetics. It is difficult to choose which one to dive in. But I think this is one of the decent one. I like it. I found the site in an effort to learn more about various cults. If you want to survey various kinds of cults, this site can provide a simple guideline. Basically if you don’t know about cult and heresy, which means you don’t know the orthodox. As Christians you can’t understand heresy without understanding what the Christian orthodox is because heresy is something that is not orthodox. If you have a strong foundation of Christian theology, heresy would not be something to be afraid of. It is very interesting to find out commonality among many heresies. They are all based on sinful human nature and humanism.