What am I?

People get their impressions of me based on what they see from me. While my colleagues tell me I am a writing machine or a prolific writer, students think I am thoroughly prepared. But I see myself differently. I'm always conscientious and feel like walking a tightrope. The other day I wrote about myself below:

Like a vapor, I am evanescent.
Like a reed, I am wavering.
Like dust, I am small.
But I'm not vanity.
I am a gift of God.