There are many different ways that the power of a word is expressed in the New Testament. In most cases, this power is bound to the person of Jesus Christ, and its outcome is positive. Through his word Jesus not only heals, exorcizes, and brings the dead back to the life, but he also curses. This thesis discusses the question, what the New Testament says about various imprecations, maledictions and many other negative appearances of a word and the demonstrations of its power. This thesis comprises an overall outline of the passages from the New Testament and their commentaries, which appear to be close to the selected theme. In the first part the thesis deals with the notion and relevance of a "word" and "human speech" for people and their relationship with God. In the second part, this thesis delves into the area of imprecations and maledictions. The third part is dedicated to promises and oaths. The fourth part aims to the theme of wrath and how its expressed in words in the texts of the New Testament, that are connected with the selected theme, including the commentaries. The aim of the thesis is primarily to present the issue of the impact of negative words on human life including the accessible interpretations of selected parts and their evaluation, which is a subject, in my opinion, that in general...