It is easy to lose our focus when we are busy working for God. We get distracted by our agenda or pride and we can substitute God's best for what we thought was a good idea. Our good intentions to help people can distract us from our priority.
We need to be constantly reminded that we are to focus on God's kingdom and his glory in every aspect of our trip. We become powerful weapons that God is willing to use if we acknowledge our dependence on him before, during and after the trip.
We need to remember that our trip is a short term thing in the bigger picture of God's plan to build his kingdom and bring glory to himself. Our short term goals need to always fit into the larger context of God's ultimate purpose. With that in mind we need to always be sensitive to his leading and be willing to join him where he is already working.