It’s easy to underestimate the power of one person’s influence. We think, What can I do? I am only one person. Even when I was the CEO of a company I often felt this way.

The truth is that each of us wields far more power than we could possibly imagine. However, most of us have never discovered this—or we have forgotten it.

What does marriage have to do with leadership? If you are married, everything. Nothing will undermine your effectiveness as a leader faster than a bad marriage. Your marriage is a living example of what it is like to be in a close relationship with you. This is why it is so important that leaders get this right if they want to influence others.

Unfortunately, we live in a culture that is very me-centered. Gail and I often talk to people who are frustrated with their spouses. Most of this stems from the fact that they are not getting what they think they need or what they think they should be getting.

To be a true influencer in the lives of those you lead, you must understand a simple, but powerful question. It is one your followers are asking. It goes like this: “Are you for me, against me, or for yourself?”

It is a great question, one that is asked by those you and I lead at least once within the relationship. Once the question has been confirmed, it rarely comes up again. Our followers know our intent towards them or at least towards ourselves.

Many people have written on what it means to be a leader. Almost everyone identifies influence as the primary characteristic. By definition, this means that leadership and position are two different things. You can have a title, and a position of power, but this does not mean that you are a leader. Even people without these things can exert influence and thus leadership.

Twitter is a great tool for extending your influence. You can engage your “tribe” in real time, offering leadership and assistance in a way that would have been impossible just a couple of years ago.

A few weeks ago, I was called by a consultant who was prospecting for business. He was a friend of a friend, so I felt duty-bound to give him thirty minutes to tell me about his company and the service he provides. Sadly, it was a complete waste of time.

There are numerous things you have zero control over. You can’t control the weather, the economy, or the actions of others. Yes, you might be able to exert some influence, but this is different than control.

Leadership is about influence not control. I am not the first person to make this observation, but it is worth repeating.