The Old Testament lays the foundation for the teachings and events outlined in the New Testament. The New Testament can only be fully understood when seen as a continuation of the description of events, heroes, laws, the system of sacrifices, covenants, and promises written in the Old Testament. If we had only the New Testament, then starting to read the Gospels, we would not know why the Jews expected the Messiah so much. Without the Old Testament, we would not understand why this Messiah had to come. We would not be able to identify Jesus of Nazareth as the Messiah from the many detailed prophecies about Him. In particular, it is crucial to understand what meant mercy and compassion in both testaments because these concepts are basic for the religion.
In the Old Testament, the concept of mercy has a long and rich history. Christ, revealing mercy through His deeds and His teachings, turned to people who were not only familiar with the idea of compassion, but also derived from their history some special experience of knowing the mercy of God. This experience was not only social and communal, but also personal and internal. Every time Israel began to realize its unfaithfulness to God, it prayed for mercy. In the sermons, the prophets associated mercy with the image of God’s ardent love for His people. The Lord forgave Israel for transgressions and sins when He saw repentance and genuine conversion, and again confirmed His people in merciful grace.
This belief is based on the foundational experience of a people living in exile. The Lord, seeing the miserable condition of His people, taken into slavery, hearing their cries, felt longing and decided to free them. In this salvation accomplished by the Lord, the prophets recognize His love and His compassion. This is how the trust in Divine mercy was rooted. Besides, one of the reasons for such a miserable condition is sin. The people of the Old Testament knew this insignificance at the time of the Exodus, when the golden calf was erected. After all the falls, the people and each individual person found the strength to turn to the Lord in order to ask Him for merciful forgiveness.
In the New Testament, the motives of mercy and compassion for one’s neighbor are expressed much more strongly than in the Old. However, both the Old and New Testaments the preaching of brotherly mercy and love for one’s neighbor reveals only one side of that contradictory religious morality, the reverse side of which is precisely the preaching of cruelty and heartlessness in relations between people. As for the proper New Testament morality, its characteristic feature is a pronounced duality. What is recommended to the oppressed and exploited is not recommended to slave owners and other powerful people. In the New Testament, it is easy to see that forgiving offenses, putting our cheeks under the blows, not resisting is prescribed only to the oppressed. The oppressors, on the other hand, are encouraged to kill anyone who tries to resist them.
Some believers argue that people just have to follow New Testament teaching. The point is not what actions are attributed to individuals or even to God, but what the new Testament calls for. From this point of view, it does not matter whether certain biblical characters act mercifully, it is important that the very call for brotherly love between people, for mercy, forgiveness of offenses, for refraining from violence is salutary for humanity.