Translation
Now if I cast out demons by Beelzeboul, by whom do your sons cast them out? In this way they will be your judges.
Paraphrase
You say that I am casting out demons using the power of Satan; do you say that those among you who cast out demons do so by relying on the power of Satan? NO! Therefore, you are condemned by your duplicity for you are not consistent in your interpretation of my actions and the actions of your own people.