We can see this lesson as a series of reasons to let the Holy Spirit speak through us today.
Reason 1: Unless we allow Him to speak through us, the world will not hear God's Voice. God cannot just speak directly to the world, as a booming voice in the clouds. He needs people who will hear His Voice in their minds and pass on what It says. That is why it is so crucial for us to accept the role of being His mouthpiece. Think about this: the Holy Spirit really does need your voice today (1:1).
Reason 2: Only God's words and thoughts are true (1:2). If you are not letting Him speak and think through you, you are thinking false thoughts and speaking lies. How does it feel to really consider you are doing that?
Reason 3: You have damned the world and this is your chance to set it free (1:3-4). Wouldn't you want to be able to set straight such a grievous mistake?
Reason 4: By damning the world, you sentenced yourself to hell. By setting the world free, you set yourself free (1:4). By letting the Holy Spirit redeem the world, you let Him rescue you from hell (2:3). By letting Him speak through you, you will also let Him speak to you (1:4). You finally allow yourself to hear the beautiful message of freedom He has been waiting to give you for eons.
Reason 5: We have been wanting to let the Holy Spirit speak to us. We have been wanting to hear Him tell us that we are still loved, that we have not been forgotten, regardless of what we have done. But we have been teaching our brothers a different lesson. And this conflict of lessons—trying to learn the opposite of what we are teaching others—has made for very slow progress. If you wonder why your progress on the spiritual path seems slow, this may be a big reason why. The way to speed up that progress is to teach to others the same lesson you are trying to learn yourself. That way, all your oars will be pulling together. "And so our learning goal becomes an unconflicted one, and possible of easy reach and quick accomplishment" (2:2). Today, we want to hear the Holy Spirit speak His message of love to us, and so that is what we will speak to others.
Stories of letting Him speak through people
What does it look like to let Him speak through us? It will probably look quite ordinary. The early dictation of the Course includes several stories of someone being inspired to say something helpful, something loving to someone else, and those words were called a miracle, since miracles are expressions of love. For example:
Jesus referred to the dictation that Helen was taking down from him as "miracle-working," because the words she wrote down could be useful for others (as we students of the Course can amply attest).
Mrs. Albert, by the bedside of the dying Dave Diamond, expressed her unembarrassed conviction that God could come and say "Get up, Dave," and then he would. Jesus called it a miracle.
Jesus referred to a line written by astrologer Jeane Dixon about "Feet on the ground and fingertips in the Heaven" as a miracle.
Jesus said that he could use Bill's talent for puns as a means of miracle-working, if Bill would allow him to. And then he gave an example: He talked about remembering God not as a remembering of the past but as a "real re-membering"—like reattaching a detached member.
Jesus said that he inspired Bob, the elevator operator who took Helen down from her apartment, to make a remark to her which ended with, "Every shut eye is not asleep." This theme then showed up in Jesus' teaching in the Course.
Helen, while waiting for a taxi to take her home from work, was irritated with a developmentally disabled girl, who was causing the door to be held open too long each time it was opened, thus letting cold air in on Helen. Helen was so concerned about her own discomfort, she rather densely failed to notice the girl was developmentally disabled, which happened to be her professional specialty. Jesus implied that, instead, Helen could have given her a miracle in the form of a confidence-building message: "It would have been much wiser had you built up her confidence, instead of associating with her stupidity."
As you can see, letting the Holy Spirit speak through you is quite an ordinary-looking thing. You may be passing on a larger truth, in some way the other person will find helpful, or you may just be building up someone's confidence. If you turn within, there is Something in you that will know. There is a loving impulse that will want to bubble up and come through you.
You may want to think of the people you expect to interact with today, and with each one ask the Holy Spirit the following questions (the second one is based on the statement in Lesson 276 that God's Word is "My Son is pure and holy as Myself"):
What would You say through me to [name]?
How would You have me tell [name] that he/she is pure and holy as God Himself?"
Quiet your mind. Try to clear it of any preconceptions. Listen deeply. Repeat your questions if nothing comes at first. You may want to have pen and paper in hand, and write down anything that comes to mind.