The work by St. Nicetas emphasizes the Apostle's teachings on the necessity of good works for believers aspiring for the heavenly kingdom. It critiques various heresies, particularly those of Sabellius, Photinus, and Arius, which distort the understanding of the Trinity and the relationship between the Father and the Son. The author defends the Nicene formulation that the Son is of the same substance as the Father, asserting that both are fully divine and distinct. The document concludes by urging believers to honor both the Father and the Son, maintaining their unity in will and governance.