One of the original Greek words used in the New Testament for gospel preaching means “a public proclamation by a herald”. In those days heralds represented kings, princes, military leaders, magistrates or civil authorities, personally and publicly conveying their messages to the people, unchanged and with clarity and solemnity. Such heralding emphasized the representative character of the commissioned herald, and the seriousness, dignity and authority of his proclamation, since it is “always with the suggestion of formality, gravity and an authority which must be listened to and obeyed” (Thayer’s New Testament Greek Lexicon).
There are a lot of other words used as well. My old seminary professor William Schmelder wrote about the paucity of language that we use in describing and Heralding the Gospel. There are 30 some vocables used for heralding the good news in the Bible. He lists the depth and breath of meanings that come from those vocables than most of us simply translate as “preach”. The concern is we lose something which was a living reality in the early church. Preaching is a form of exhortation. To exhort people in the name of Christ is the equivalent of the sermon. Sometimes it means to “herald the Lord” with exultation. In Hebrews 13:22 “exhortation” is used for up building the household of God. Preaching is to encourage and console. It is to appeal. This word can take on the connotation of a reasoned argument for the good news of Jesus against the bad news of the world. It can be a careful side-by-side examination of facts. It can be teaching, and setting forth the truths of the scripture and what they tell us of Christ and how we are in Christ. It can be the reading of Scripture, as the reader witnesses to the truths of God’s Holy Word.
Thirty times in the New Testament there is a specific Greek word used as a way of talking about preaching and it comes across as “comforting exhortation”. The greatest possible comfort comes from the doctrine of Justification and the highest worship in the gospel is the desire to receive forgiveness of sins. Preaching is fundamental to the church.