Words can create...
The Bible is FULL of things people say. If you ever listen closely to a Torah reading, you'll hear that the words vayomer (he said), vayikra (he called) and vayedaber (he spoke) are the three default verbs.
But at first, words are not only about speaking, they're about creating. THE Creation is basically a speech! God didn't make a sculpture, use a magic wand, bake a cake, etc.: God said words and these words created a World
Eliezer Ben-Yehuda, creating a language to create a political reality (from Wikipedia)
In 1881 Ben-Yehuda immigrated to Palestine, then ruled by the Ottoman Empire, and settled in Jerusalem. Motivated by the surrounding ideals of renovation and rejection of the diaspora lifestyle, Ben‑Yehuda set out to develop a new language that could replace Yiddish and other regional dialects as a means of everyday communication between Jews who moved to Israel from various regions of the world. Ben-Yehuda regarded Hebrew and Zionism as symbiotic: "The Hebrew language can live only if we revive the nation and return it to the fatherland," he wrote.
To accomplish the task, Ben-Yehuda insisted with the Committee of the Hebrew Language that, to quote the Committee records, "In order to supplement the deficiencies of the Hebrew language, the Committee coins words according to the rules of grammar and linguistic analogy from Semitic roots: Aramaic and especially from Arabic roots"
Words can destroy
There are several Jewish commandments/prohibitions connected to speech in Judaism. In the Bible, here is a strong prohibition against false-witnessing (in the Ten Commandments), and others about gossiping, badmouthing, etc. as well as several stories of crises stirred by a misuse of speech.
In rabbinic thought, humiliating someone in public is assimilated to homicide. See excerpt below of the Babylonian Talmud:
כל המלבין פני חבירו ברבים כאילו שופך דמים
Anyone who humiliates another in public, it is as though he were spilling blood.