The verse says: “Vanities of vanities, said Koheles, vanity of vanities, everything is vanity” (Ecclesiastes 1:2). On this, the Zohar comments that since the word hevel (“vanity”) also means “breath,” it can be read, “…everything is breath.” What does this mean? Rebbe Nachman of Breslov tells us it means everything depends upon the breath of our mouths, on the way we use the power of speech (see Likutey Moharan I:49,5).
Our words of prayer and Torah study have an immense effect on the way G-d runs the universe. Words of holiness can bring repair and healing to the entire world; words of unholiness can bring ruin and destruction.
Rebbe Elimelech of Lizensk once said that it caused him great anguish to see the thousands of “castles of impurity” that were constructed every day in the spiritual worlds as a result of the sins of the wicked. His only consolation, he said, was that towards the end of the day, his student, the great Chozeh of Lublin, would stand up for the afternoon prayers, and with his words of prayer he would demolish all the structures of impurity that had been built during the day. Everything depends upon our words. With them, we can build “castles of impurity,” or we can tear them down and build worlds of holiness (see sefer Chafetz Chaim, Introduction).
Even our portion in the World to Come depends on what we do with words. According to the sefer Arvei Nachal, if a person wants to know whether or not they have a place in the World to Come, they should examine the way they use their mouth. If their mouth is regularly filled with words of holiness, with words of Torah and prayer, and if their mouth is free from unholy words, from gossip, slander, and profanity, then they can be sure that they have a place in the World to Come (Arvei Nachal, parshas Bereishis, drush 11). According to the way we use the power of speech in this world, so will it be in the World to Come!
May Hashem help us to guard our mouths from improper speech and to use our mouths for holiness always!