In connection with its intense patriotism, Jahvism from the beginning must have been distinguished by a rigid exclusiveness. The greatest danger it had to face was the corruption of the Israelites by the religions of the peoples around them. To guard against this danger, it would naturally insist on the sternest separation of Israel from the Gentile nations. Circumcision, as well as other local customs, it used as means of fulfilling its purpose. Jahvism was probably at first fiercely cruel. The injunctions to extirpate the Canaanites contained in the books of the law, which Professor Kuenen considers to be the expression of the Jewish hatred of foreigners after the captivity, and only “murder on paper,” in all likelihood faithfully represent the feelings of the Jahvists in early times. They must have seen their fellow Israelites constantly deserting Jahveh for the gods of other peoples, and it is natural that they should have wished to remove such temptations in the most effective manner. Probably they did not succeed in gratifying their desires, except in a few instances when national feeling was strongly roused. The Israelites in general, we may be sure, were easily corrupted, and were in too much sympathy with foreign gods to destroy their worshippers. But the Jahvists must have been fierce haters of foreigners, and eager in every way to build an insurmountable wall around Israel. This strict exclusiveness, inevitable and, indeed, praiseworthy in early times, afterwards came into collision with the higher tendencies of Jahvism when it attained its maturity. The subsequent Messianic ideal, as it existed in the noblest minds, involved a struggle against these influences, which, in its youth, had been a hard shell enclosing and protecting the Jewish religion. For the most part the battles of Jahvism must have been with the local religions of the lands the Israelites conquered.[19] Intermixing with the conquered peoples, in race kindred to themselves, they would readily adopt the divinities they found in possession of the soil. Thus, in different districts, Jahvism was opposed to different religions[20]—a fact which was afterwards the subject of the bitter irony of Jeremiah.[21] But its longest and most important conflict was with the religion of Baal, some particular deity worshipped under this generic title. The history of Elijah illustrates the severity and uncertainty of the struggle. To the Jahvists probably its fierceness was wholly due. They would tolerate the existence of no other religion, and so, in self-defence, other religions were bound to persecute them. This long contest with Baal must have been of great service to Jahvism.[22] It strengthened the fanaticism of the Jahvists, and showed vividly to the people the zeal their religion inspired. When actually put face to face with other gods, the superiority of Jahveh must have been so manifest as to gain for him many adherents.