One of the important aspects for all jobs, including Christian ministry is ones capacity to carry out the job. If you have 100% capacity to do a job then there is a good chance that it will become pretty boring after a while. Not much of a challenge.
The best type of situation is where there is constantly a need to increase skills, in that way there is always a challenge. In this respect capacity is about 80-90%
The worst situation is when someone just doesn't cut, they don't for what ever reason just don't have the skill level, to complete the job. Capacity is between 0-80%
Capacity for Church ministry is made up of a few things, and I'm sure others may have some other reasons. As I've all ready mention skill is real important, passion, vision, implementation, communication and time. For Christina and myself our biggest limitation is time, especially with two toddlers.
The good thing about a Christian community, is other can complement some of the leaders capacity.