Reference: Baalzebub (Beelzebub
Hastings
A Philistine god worshipped at Ekron (2Ki 1:2-3,6,16), whose name in the form of Beelzebul (AV and RV Beelzebub) has been applied to the 'prince of the devils' (Mt 10:25; 12:24; Mr 3:22; Lu 11:15,18-19). The OT form, 'Baal (controller, inhabiter) of flies,' indicates either that the god was thought to appear as a fly, or that, besides oracular powers, he possessed the ability to increase or destroy these insects. On the other hand, if the NT spelling, 'Baal of the mansion (temple),' is to be preferred, it would seem to indicate that the OT form is a deliberate perversion originating with some pious scribe, who was perhaps offended at such a title being given to any other than Jahweh. Such an interpretation would account for the variation in spelling, and for its application to Satan, whose realm was called 'the house' par excellence among the Jews of the NT period.
N. Koenig.