What is the biblical basis for the centrality of preaching in worship?

In 1 Corinthians 12:27-31:

Now you are the body of Christ, and each one of you is a part of it. And God has placed in the church first of all apostles, second prophets, third teachers, then miracles, then gifts of healing, of helping, of guidance, and of different kinds of tongues. Are all apostles? Are all prophets? Are all teachers? Do all work miracles? Do all have gifts of healing? Do all speak in tongues? Do all interpret? Now eagerly desire the greater gifts.

Apostles can promulgate new doctrine under divine inspiration as well as plant churches. They circulated letters that were to be read by the churches in their worship services. Among other things, theirs was a teaching ministry.

Prophets apply existing doctrine to specific individuals or situations, or foretell future events. In 1 Corinthians permission is given for two or three prophets to speak during a service.

Teachers (or pastor-teachers) teach.

These first three gifts are spoken of as the three most important, therefore the role they play in the life of the church is most important. Each is spoken of as contributing to the worship service.

Concerning apostles, see Colossians 4:16 -

After this letter has been read to you, see that it is also read in the church of the Laodiceans and that you in turn read the letter from Laodicea.

Concerning prophets, see 1 Corinthians 14:29 -

Two or three prophets should speak, and the others should weigh carefully what is said.

As for teachers, their role was common in Judaism in synagogue. Noteworthy is Nehemiah 8, where Ezra the scribe read from the book of the law from morning to night for seven days as the people listened, so moved by contrition that they had to be told not to weep.

1 all the people came together as one in the square before the Water Gate. They told Ezra the teacher of the Law to bring out the Book of the Law of Moses, which the Lord had commanded for Israel.

2 So on the first day of the seventh month Ezra the priest brought the Law before the assembly, which was made up of men and women and all who were able to understand. 3 He read it aloud from daybreak till noon as he faced the square before the Water Gate in the presence of the men, women and others who could understand. And all the people listened attentively to the Book of the Law.

4 Ezra the teacher of the Law stood on a high wooden platform built for the occasion. Beside him on his right stood Mattithiah, Shema, Anaiah, Uriah, Hilkiah and Maaseiah; and on his left were Pedaiah, Mishael, Malkijah, Hashum, Hashbaddanah, Zechariah and Meshullam.

5 Ezra opened the book. All the people could see him because he was standing above them; and as he opened it, the people all stood up. 6 Ezra praised the Lord, the great God; and all the people lifted their hands and responded, “Amen! Amen!” Then they bowed down and worshiped the Lord with their faces to the ground.

7 The Levites—Jeshua, Bani, Sherebiah, Jamin, Akkub, Shabbethai, Hodiah, Maaseiah, Kelita, Azariah, Jozabad, Hanan and Pelaiah—instructed the people in the Law while the people were standing there. 8 They read from the Book of the Law of God, making it clear[a] and giving the meaning so that the people understood what was being read.

9 Then Nehemiah the governor, Ezra the priest and teacher of the Law, and the Levites who were instructing the people said to them all, “This day is holy to the Lord your God. Do not mourn or weep.” For all the people had been weeping as they listened to the words of the Law.

10 Nehemiah said, “Go and enjoy choice food and sweet drinks, and send some to those who have nothing prepared. This day is holy to our Lord. Do not grieve, for the joy of the Lord is your strength.”

11 The Levites calmed all the people, saying, “Be still, for this is a holy day. Do not grieve.”

12 Then all the people went away to eat and drink, to send portions of food and to celebrate with great joy, because they now understood the words that had been made known to them.

13 On the second day of the month, the heads of all the families, along with the priests and the Levites, gathered around Ezra the teacher to give attention to the words of the Law. 14 They found written in the Law, which the Lord had commanded through Moses, that the Israelites were to live in temporary shelters during the festival of the seventh month 15 and that they should proclaim this word and spread it throughout their towns and in Jerusalem: “Go out into the hill country and bring back branches from olive and wild olive trees, and from myrtles, palms and shade trees, to make temporary shelters”—as it is written.[b]

16 So the people went out and brought back branches and built themselves temporary shelters on their own roofs, in their courtyards, in the courts of the house of God and in the square by the Water Gate and the one by the Gate of Ephraim. 17 The whole company that had returned from exile built temporary shelters and lived in them. From the days of Joshua son of Nun until that day, the Israelites had not celebrated it like this. And their joy was very great.

18 Day after day, from the first day to the last, Ezra read from the Book of the Law of God. They celebrated the festival for seven days, and on the eighth day, in accordance with the regulation, there was an assembly.

With the passing of the apostolic age and the rarity of true prophets in our times, this leaves the gift of teacher as the most important, hence establishes its centrality in worship.

However, I would stress that the same passage that names some gifts as more important than others also cautions against spiritual pride and proclaims that all the gifts are essential to strengthen the Church.

The prophet, as spokesperson for God, is the biblical basis for the centrality of preaching in worship. From the very beginning, and over and over since, God’s people are exhorted to listen.

Moses, probably through Aaron ¹, said that God’s people should listen to God’s prophets.

The Lord your God will raise up for you a prophet like me from among you, from your fellow Israelites. You must listen to him. (Deuteronomy 18:15)

Moses reminds God’s people that they asked for these spokespersons so they would not have to ever again fear and tremble at the direct word from God’s mouth.

For this is what you asked of the Lord your God at Horeb on the day of the assembly when you said, “Let us not hear the voice of the Lord our God nor see this great fire anymore, or we will die.” (Deuteronomy 18:16)

To which God commissions the prophet to proclaim God’s divine will.

The Lord said to me: “What they say is good. I will raise up for them a prophet like you from among their fellow Israelites, and I will put my words in his mouth. He will tell them everything I command him. (Deuteronomy 18:17-18)

And over the next several hundred years, God’s prophets continued to make declarations of God’s divine will.

“Go and tell this people.” (Isaiah 6:9)

“Speak my words to them, whether they listen or fail to listen.“(Ezekiel 2:7)

“Go, prophesy to my people Israel.“ (Amos 7:15).

Jeremiah, toward a semblance of a ‘worship service’, makes a famous preaching engagement at the temple:

Stand at the gate of the Lord’s house and there proclaim this message: “Hear the word of the Lord, all you people of Judah who come through these gates to worship the Lord.” (Jeremiah 7:2)

Hear. Listen. Shema. ²

Into which comes the forerunner, the baptist John, recognized as prophet before he was born.

“And he will go on before the Lord, in the spirit and power of Elijah.” (Luke 1:17)

The common people identified Jesus among John and the prophets.

They replied, “Some say John the Baptist; others say Elijah; and still others, Jeremiah or one of the prophets.” (Matthew 16:14)

Jesus Christ identified himself with the prophets.

A prophet is not without honor except in his own town and in his own home. (Matthew 13:57)

At Jesus’ transfiguration, again God’s intimidating direct word from the cloud, words that echo Jesus’ baptism.

This is my Son, whom I love; with him I am well pleased. Listen to him! (Matthew 17:5)

The early church took Christ to be God’s promised prophet of Deuteronomy 18 who would proclaim God's word in the same fashion as did Moses. But still, God’s people need other humans to help them listen and hear.

And how can they hear without someone preaching to them? (Romans 10:14)

And finally, in what probably speaks most to the nebulous protestant preacher of the question, we have Paul’s slow burn of a command to Timothy:

In the presence of God and of Christ Jesus, who will judge the living and the dead, and in view of his appearing and his kingdom, I give you this charge: Preach the word. (2 Timothy 4:1-2)

In conclusion, prophet is preacher throughout scripture entire and is the basis for the centrality of preaching to anything at all resembling the worship of God.

¹ From the moment of Moses’ original commission, Moses objected to God that he could not speak because he was “slow of speech and slow of tongue.” God provided Aaron, one of the first appointed to speak God’s word.

² Shema Yisrael (or Sh'ma Yisrael; Hebrew: שְׁמַע יִשְׂרָאֵל‎; "Hear, [O] Israel") are the first two words of a section of the Torah, and is the title (sometimes shortened to simply Shema) of a prayer that serves as a centerpiece of the morning and evening Jewish prayer services