He charged them to take nothing for their journey except a staff—no bread, no bag, no money in their belts— but to wear sandals and not put on two tunics.
Mark 6:8-9

This wasn't a general command to all missionaries and evangelists. It was meant to be a wilderness/training experience for the Twelve Disciples in which they would learn to trust God for everything. It doesn't mean we shouldn't plan and prepare for ministry. It means we should trust God, not money or ourselves.