Preaching is an utterance containing the essence of Christ. Preaching is a Christ-filled proclamation. It is an impartation of Christ through proclamation.

Vine's says: “The substance of what is preached as distinct from the act of preaching.” Strongs says: "(1) that which is proclaimed by a herald or public crier, a proclamation by herald (2) in the NT the message or proclamation of the heralds of God or Christ" These come closer to the meaning.

Note that Strongs doesn't say, "heralds of thoughts about God or Christ." Strong's says: "heralds of God or Christ" That is, the essence of God, the essence of Christ, is contained in the utterance. By the context of how kerugma is used in the New Testament, we can see that this isn't a kind of preaching that proceeds from human reasoning. It is the Utterance of Christ that is spoken by the Holy Spirit and contains the Power and Presence of Christ Himself.

Keep in mind that Jesus Christ is the logos of God. That is to say, He is God's utterance. Those who follow Christ are to speak as the oracles of God, the very mouthpieces of God. God is to speak through us in everything.

It is interesting to note that the word, "logic," comes from the Greek word, "logos." The logic that is taught in schools cannot have any value.

A skeptic named Agrippa, in the First Century after Christ, saw the limits of human logic. Agrippa realized that all human thought (without Divine revelation) must be based on one of these three fallacies: infinite regress, circular reasoning, or axiomatic thinking. This has become known as Agrippa's Trilemma. Knowing this destroys all secular thinking. All secular science and logic is based on infinite regress, circular rasoning, or axiomatic thinking. The only things we can know are those things that God has revealed to us personally. To receive the teaching of a teacher sent from God, Divine revelation is needed. Otherwise, how would anyone be able to discern between the true teacher and the false teacher, the true prophet and the false prophet? By their works shall you know them, but not by the weakness of human reasoning.

Through 1 Corinthians 1:21, God tells us that, in His wisdom, the world doesn't come to know God by means of human philosophy and reasoning, but it pleased God to save those who receive His supernatural belief and trust by what the ungodly call the "foolishness of the impartation of Jesus Christ through proclamation." Whenever you hear a philosopher, politician, theologian, scientist, or evangelist casting verbal arguments in the trappings of logic, the person is proclaiming Jesus Christ or else speaking by means of human philosophy and reasoning. Theories can only give rules of thumb that seem to work in a pragmatic way, at least most of the time. The Law was given as a Divine revelation; however, the people turned it into a human interpretation through philosphy and reasoning. Truth comes through  the impartation of Jesus Christ through proclamation. No wonder the fool has said in his heart, “There is no God.”

07150 ker-ee-aw’
from 07121; n f; {See TWOT on 2063 @@ "2063c"}
AV-preaching 1; 1
1) proclamation, preaching

2784 kerusso kay-roos’-so
of uncertain affinity; TDNT-3:697,430; {See TDNT 385} v
AV-preach 51, publish 5, proclaim 2, preached + 2258 2, preacher 1; 61
1) to be a herald, to officiate as a herald
1a) to proclaim after the manner of a herald
1b) always with the suggestion of formality, gravity and an authority which must be listened to and obeyed
2) to publish, proclaim openly: something which has been done
3) used of the public proclamation of the gospel and matters pertaining to it, made by John the Baptist, by Jesus, by the apostles and other Christian teachers

2782 kerugma kay’-roog-mah
from 2784; TDNT-3:714,430; {See TDNT 385} n n
AV-preaching 8; 8
1) that which is proclaimed by a herald or public crier, a proclamation by herald
2) in the NT the message or proclamation of the heralds of God or Christ

2097 euaggelizo yoo-ang-ghel-id’-zo
from 2095 and 32; TDNT-2:707,267; {See TDNT 268} v
AV-preach 23, preach the Gospel 22, bring good tidings 2, show glad tidings 2, bring glad tidings 1, declare 1, declare glad tidings 1, misc 3; 55
1) to bring good news, to announce glad tidings
1a) used in the OT of any kind of good news
1a1) of the joyful tidings of God’s kindness, in particular, of the Messianic blessings
1b) in the NT used especially of the glad tidings of the coming kingdom of God, and of the salvation to be obtained in it through Christ, and of what relates to this salvation
1c) glad tidings are brought to one, one has glad tidings proclaimed to him
1d) to proclaim glad tidings
1d1) instruct (men) concerning the things that pertain to Christian salvation