I was speaking with a friend about the lessons we learn from the people we encounter in our lives. Few of these people consider themselves to be teachers, but they are teaching us important lessons. I have come to accept that all people are teachers with lessons for our growth. Though this may be easy to accept with people I like and admire, how can this be with people who challenge me? I thought this would be a good conversation to have with my inner voice.
Am I right in thinking that all people are teachers with important lessons for growth?

That is correct. All people — good, bad, or indifferent — are placed along your path to teach you the lessons you need to learn in your life. The important thing to focus on is that there are positive lessons to learn from negative experiences. As you know, not every encounter is positive or loving. In such situations, sifting through the experience to find the positive lesson will benefit you. Remember, even the quickest interaction has a lesson for you to find and use to grow.