In his book Speaking God’s Words: A Practical Theology of Preaching, Peter Adam gives three biblical foundations of preaching:
1. God has spoken.
Without God’s words there can be no ministry of the Word. If God is dumb, we may speak, but we cannot speak God’s words, for there are none to speak. The first great theological foundation for preaching, then, is that God has spoken.
2. It is written.
The second great foundation for preaching is that It is written. This is the belief that in his revelation in history God also preserved his words for future generations. It is on this basis that our teaching and preaching are based on the Bible. On many occasions when God spoke, his intention was not only that his words would constitute revelation to the original audience, but that they would also serve as revelation for future generations.
3. Preach the Word.
Our third foundation is found in the phrase Preach the Word. That is to say, preaching depends not only on having a God-given source, the Bible, but also a God-given commission to preach, teach and explain it to people and to encourage and urge them to respond. The origin of the ministry of the Word is that God has given his words to his servants to pass on to others.
Defined theologically, then, preaching is the act of speaking to others what God has already spoken and preserved for our benefit. What a privilege! What a responsibility.