Am I Making a Difference?

Not too long ago I lamented (openly, verbally) that I wasn't sure how much affect I was having in the Kingdom. Preachers do this...some more than others. I think I was just tired and feeling Satan's arrows. It was a down time for me. Was my preparation a waste of time? Were people really listening to me? Do people really care?
Dumb move. First of all, to wonder if I (meaning one person) is having an affect is useless and vain. Because, it's not about me. It's about the One we proclaim. "Let your light shine so that they may see your good works and glorifying your Father who is in heaven." So my first mistake was putting myself on the throne.
But God in His mercy pushed back the curtain just a little bit to let me see. I had a young father come to me right after a sermon I had preached. He told me of some struggles he was having with his son. I had just preached a sermon on the prodigal. The young father was ready to call it quits. My sermon had said never shut the door because God never shuts the door on us. He told me he would never shut the door on his son. Then I saw a facebook entry that talked of a wonderful service that we had had recently on Father's Day. He talked of how much it meant to him and that I had planned it.
I hung my head. Shame on me. I was worried about what people were thinking of me instead of letting people see how great He is.
Thank you, God, for showing me that Your words don't come back void. Forgive me when I get caught up in the preacher thing about really making a difference. Help me to see that it has nothing to do with me, but everything to do with You. I love you, Lord.