During the preparation process, the answer is simple: procrastination. Delay in asking questions, delay in making a decision to go, delay in sending out support letters, delay in beginning daily prayer for the Lord to bless your faithfulness. Satan is never threatened by someone who will neutralize themselves by putting off important decisions. On the field, team members miss out on blessing (or cause other people to miss blessings) by being inflexible or proud. You are responsible for positioning yourself to receive the blessings that come from giving your best to the Lord in this process and being both flexible and humble in the field.