But Osiander's house had another attraction of a different kind from theological sympathy.
He was against the Leipzig Interim (1548) with its compromise on some Catholic usages, and was involved in controversies and quarrels; with Georgius Merula, against whom he maintained the need of exorcism in baptism; with Osiander's adherents in the matter of justification; with his colleague, Nicholas von Amsdorf, to whom he had resigned the Eisenach superintendency; with Flacius Illyricus, and others.
Osiander's divergence from Luther's doctrine of justification by faith involved him in a violent quarrel with Melanchthon, who had adherents in Konigsberg, and these theological disputes soon created an uproar in the town.
After Osiander's death in 1552 he favoured a preacher named John Funck, who, with an adventurer named Paul Scalich, exercised great influence over him and obtained considerable wealth at the public expense.
Osiander's son Lukas (1534-1604), and grandsons Andreas (1562-1617) and Lukas (1571-1638), were well-known theologians.
Osiander's theory did not win much support, but it was the starting-point of two separate doctrines.
In 1553 Duke Albert of Prussia, anxious to heal the differences in the Prussian church caused by the discussion of Osiander's doctrines, invited him to Konigsberg, and in the following year appointed him professor of divinity and president of the Samland diocese.