12.1.6.2 The proclamation of the word in the New Testament
While believing people already proclaimed the will of God through the power of the Holy Spirit during the time of the Old Testament, a new dimension of God's word became reality with the birth of the Son of God. In Jesus Christ the Word of God came to mankind in perfection.
Jesus taught in the temple in Jerusalem, in synagogues, and in other places. Much of the content of His sermons has been handed down to us in the gospels, which contain the basic principles of Christian doctrine. When He preached, Jesus used parables and interpreted the Old Testament. Furthermore, He made many references to the future. For instance, He foretold His own suffering, resurrection, and ascension into heaven, and gave the promise of His return. The outstanding nature of Jesus' preaching is illustrated in the Sermon on the Mount, which contains the beatitudes and many statements that had never been heard before. The effect of this sermon is shown in the reaction of His audience: "... the people were astonished at His teaching, for He taught them as one having authority, and not as the scribes" (Matthew 7: 28-29).
Although the Son of God had already assigned the Apostles the task of preaching the word during His activity on earth (Matthew 10: 7), after His resurrection He commissioned them to go into all the world and preach the gospel to all (Mark 16: 15).
Apostle Peter preached the first Christian sermon on Pentecost (Acts 2: 14 et seq.). Other sermons of the early Apostles can be found, for example, in Acts 3: 12-26; 17: 22-31. Beyond that, many of the letters of the Apostles, which were read to the believers in the congregations, can also be compared to sermons. Their contents were tailored to the congregations or the prevailing circumstances in each. They urged the members to repent, accept God's grace, and receive the sacraments. Furthermore, they were of an instructional and admonishing character. They testified of God's desire to redeem mankind and grant them eternal life in His glory.