I understand “missionaries” who go under the guise of doctors, teachers, etc. That is understandable and commendable. But each year at our church we stuff boxes for children overseas. We donate time and resources for this activity (to name but one), yet we are not allowed to put any religious material in the box or they will confiscate it (the organization). I’m not sure what is the point.
It should be a means to the end, meaning showing Christian charity in temporal matters in order to adorn the presentation of the gospel. But typically the gospel is not even presented along with the act of charity, even if only by a tract and a word of exhortation which invites dialogue, and the temporal aspect takes upon a life of its own. Read Revolution in World Missions by (Indian) K.P. Yohannan.