I know plenty of people who try to hitch these two--ambition and mission--and hope that the kingdom is served as well as the ego. In other words, hope that we can serve God and be "successful" (in the commonplace sense of that word) at the same time. But it seems to me the early disciples gave up ambition for mission. They didn't try to serve both at once.Amen.
Along similar lines, Darryl Dash really prompted a light bulb to come on in my head with his short, illuminating blog post on the desire to be forgotten.