How can people be certain that their behaviors will not harm society in the long run?

Everyone has a past, and that past can haunt our future in more ways than one. Sometimes, I forget that the words I say have an impact on society. I remember that we can use words for love and encouragement. However, I tend to forget that we can also use words for misconduct, or shameful purposes. I know that my behaviors will create chain reactions that influence the people around me. Every day, I will reach out to the people I am familiar with, strangers too, and do my best to choose my words wisely. Of course, not everything will go as planned. It is the thought of losing someone that I care about that makes me feel helpless and vulnerable. I am also afraid of bottling up my emotions to the extent that I might explode. 
Life is unpredictable, but I’m certain I can endure. The losses of each friendship that I encounter will become lessons, or knowledge, that teach me how to recognize the contrast between illusions and the real world. As time passes, I will continue to use this piece of wisdom to my advantage. Thus, I hope that this offers me a glimpse of insight, happiness, and beauty. Yes, indeed, the things that come out of my mouth and the actions I make will affect the community, but I can solve them. It is not impossible to rekindle relationships nor is it complicated to embrace change. It can take some time, but I have the power to fix things. Things won’t stay the same. At least, I’ll have a person’s shoulder to lean on. Inside every one of us is the potential to fight for whom and whatever we believe in. With this in mind, I am aware that in the long run, I can always gain a couple of wins and losses simultaneously.