Yes, I do believe that having a gun in the home helps prevent crimes. If someone breaks into your home and you are unable to defend yourself, there is a good chance you could be killed or terribly injured. It is good to be able to defend yourself and your family.
The idea that guns in homes prevent crimes is lacking in facts. Having a gun in your home does not prevent crime outside of the home and won't necessarily prevent a crime from occurring in your home. A gun will provide a level of protection if a crime were to take place and result in a different outcome as well, but they do not prevent crime.
Usually people who commit crimes don't know if the person or target actually owns a gun. It could be completely random. To be honest I think the more guns there are around the more chance of people getting shot. I think everyone would be alot safer if there were no guns at all.
No, guns in homes do not prevent crime and may in fact lead to more crime. People who keep guns in order to deter crime are not likely to stop any crime by using their gun. By the time a victim even knows there is a need for a gun, the perpetrator already has a weapon at the ready and can use it. In the meantime, scared gun owners are likely to shoot too quickly in an unnecessary situation and commit a crime themselves.