As human beings, it's sometimes difficult to believe without having seen or experienced the thing ourselves. Today, I can attest to the value and therapeutic power of witnessing, as I myself draw on the experience of others to create a means in some situations of healing, encouragement or liberation. Why do some doctors suggest group psychotherapy to their patients? Because in this therapy, they have access to other people's experience through their sharing, with visual evidence for some. For example, in one session you'll see people recovering from depression and depressed people together in the same session. The former depressive can talk about how he felt and how he coped. This will predispose the sick person to eventual recovery. Moreover, the Bible tells us that God sits in the praise of his people.
Psalm 22:3 "Yet you are the Holy One, you sit in the midst of the praises of Israel".
So by talking about what he's done for us, we create the right atmosphere for God's reign in our lives. By sharing his good deeds around us, we communicate this grace in the heart of the listener. That's why John's chapter certifies that truth makes you free. John 8:32 "you will know the truth, and the truth will set you free".
This truth becomes like a key that opens the door to all our seemingly hopeless situations. I'm convinced that once you've read everything in this book, you'll be able to take the next step in your situation.