In this quote, John Piper explains the nature of the calmness exuded by a meek person, even as they might well be accomplishing much for the Lord:
“. . . Meek people are quiet or still before the Lord and wait patiently for him. First, they discover that God can be trusted. Then, second, they commit their way to him. And then, third, they wait patiently in stillness for the work of God in their lives.
This doesn’t mean they become lazy. It means that they’re free of frenzy. They have a kind of steady calm that comes from knowing that God is omnipotent, that he has their affairs under his control, and that he is gracious and will work things out for the best. Meek people have a quiet steadiness about their lives in the midst of upheaval.”John Piper, Blessed are the Meek, February 9, 1986. Electronic edition by Logos Bible Software.