Satan and Beelzebul both mean the same prince of demons, but the Pharisees used the less-known name of Beelzebul to show their superior knowledge. Satan
refers not to his rank but to his opposition, as accuser
or adversary
of God and of human beings, especially Israel
Yes, they refer to the same prince of demons, but the two names highlight different aspects of his demonic activity. When the Pharisees invoked the less-famous name Beelzebul, it gave them an air of specialized knowledge. Yet the name Satan is what the prince of demons is more commonly known as, especially in terms of his operations in the human world beyond the bounds of his own kingdom. This name, however, does not refer to his title of rank but is rather a description of his posture toward God and humanity. He is the great adversary of all that lies outside his demonic dominion. That is how the demon intrudes upon Israel—namely, as an opponent of those created to see and to speak.1
26 Si Satan chasse Satan, il est divisé contre lui-même; comment donc son royaume subsistera-t-il?