It illustrates an important aspect of God’s calling: He can and will use anyone to achieve His purpose in drawing His people into relationship.
But it also illustrates that when we lack the faith to follow God, He will work through others who have faith. Balak, a soldier, states that he won’t go to war as God has commanded (and promised victory in) unless Deborah goes with him. Deborah replies, “I will gladly go with you,” she said, “but you will receive no honor on the road you are about to take, because the Lord will sell Sisera to a woman.”
God invites us to participate in His work, to allow Him to work through us to accomplish His purposes. If we decline, He will call someone else. His purpose WILL be accomplished, but we will miss out on the blessing of being the vessel He uses to achieve His purpose.
This story challenges me to consider what God has called me to do. Am I stepping out in faith - not faith in my own ability, but faith that the God who called me is able to accomplish it through even someone like me? Or do I look at another writer, another Bible study leader, or another speaker and defer to them? If God has called us to a particular task, passing the baton to someone else is not humility, it is disobedience.