Entrepreneurial missionary work is risky. In the space between the beginning of a project and success or dissolution, a missionary feels tension. It might not work.
He badly wants to be successful, and yet he knows he may not be. Many factors are out of his control. He cannot control people and yet his success hinges on their decisions. Can he work hard without knowing? Can he be hopeful and confident?
This is stressful. As A. J. Leon says, without the option of failure we do not have the option of success. I applaud you missionaries who are giving it your best shot, even though it might not work.