Words evoke imagination by painting that picture. A complete picture does not need to be painted or described in words in order for people to see it. When one reveals their feelings about another person to that person, the other person is going to feel something. Think of every emotion, surprise, shock, anger, love, joy and happiness. Now think about how much these emotions are evoked by words.
Words bring peace, mostly when language reveals truth.
One can feel peace when reading the Bible, having God's promises communicated repeatedly. After all, peace is freedom from disturbance. Words can say so much. It is the communication of an emotion. It can be a dream for the person hearing it, a hope that the other person will say it back, and it can also be perceived or meant as a commitment.