The second basic principle of Protestantism is salvation by personal faith. This principle was opposed to the Catholic principle of justification by works, according to which everyone who wants salvation must do everything that the Church needs, and above all contribute to its material enrichment.

Protestantism does not deny that there is no faith without good works. Good works are useful and necessary, but it is impossible to justify them before God, only faith makes it possible to hope for salvation. All directions of Protestantism in one form or another adhered to the doctrine of predestination: each person before his birth is prepared for his fate; it does not depend on either prayer or activity, a person is deprived of the opportunity to change the fate of their behavior. However, on the other hand, a person could prove by his behavior to himself and others that he was destined by the Providence of God for a good fate. This could extend not only to moral behavior, but also to luck in life situations, to the possibility of getting rich. It is not surprising that Protestantism becomes the ideology of the most enterprising part of the bourgeoisie of the epoch of the initial accumulation of capital. The doctrine of predestination justified the inequality of States and the class division of society. As the German sociologist Max Weber has shown, it was the attitudes of Protestantism that contributed to the rise of the entrepreneurial spirit and its final victory over feudalism.

The third basic principle of Protestantism is the recognition of the exclusive authority of the Bible.Any Christian faith recognizes the Bible as the main source of Revelation. However, the contradictions contained in the Holy Scripture led to the fact that in Catholicism the right to interpret the Bible belonged only to the priests. For this purpose, a large number of works were written by the fathers of the Church, a large number of resolutions of Church councils were adopted, in the aggregate, all this is called Sacred Tradition. Protestantism deprived the Church of a monopoly on the interpretation of the Bible, completely renouncing the interpretation of sacred Tradition as a source of Revelation. It is not the Bible that gets its authenticity from the Church, but any Church organization, group of believers, or individual believer can claim the truth of the ideas they preach if they find their confirmation in the Bible.

However, the very fact that there was a contradiction in the Holy Scriptures was not refuted by this attitude. Criteria were required for understanding the various provisions of the Bible. In Protestantism, the criterion was the point of view of the founder of one or the other direction, and all who did not agree with it, were declared heretics. The persecution of heretics in Protestantism was no less than in Catholicism.

The possibility of their own interpretation of the Bible led Protestantism to the fact that it does not represent a single doctrine. There are a large number of similar in spirit, but in some ways different directions and currents.

The theoretical construction of Protestantism led to changes in religious practice, which led to the cheapening of the Church and the Church ritual. The veneration of the biblical saints remained unshakeable, but it was devoid of the fetishistic elements inherent in the cult of saints in Catholicism. The refusal to worship visible images was based on the old Testament Pentateuch, which treats such worship as idolatry.

Among the different branches of Protestantism there was no unity in matters related to the cult, with the external situation of the churches. The Lutherans kept the crucifix, the altar, the candles, and the organ music; the Calvinists abandoned all this. The mass was rejected by all branches of Protestantism. Worship is conducted everywhere in the native language. It consists of preaching, singing prayer hymns, reading certain chapters of the Bible.

Protestantism made some changes in the biblical Canon. He recognized as apocryphal those old Testament works that were preserved not in the Hebrew or Aramaic original, but only in the Greek translation of the Septuagint. The Catholic Church regards them as second-canonical.

The sacraments were also revised. Lutheranism left only two of the seven sacraments — baptism and communion, and Calvinism-only baptism. At the same time, the interpretation of the sacrament as a rite in which a miracle occurs is muted in Protestantism. Lutheranism has preserved some element of the miraculous in the interpretation of communion, considering that in the performance of the rite the Body and Blood of Christ are actually present in bread and wine. Calvinism considers this presence symbolic. Some areas of Protestantism conduct baptism only in adulthood, believing that a person should consciously approach the choice of faith; others, without refusing to baptize infants, conduct an additional rite of confirmation of adolescents, as if a second baptism.