5:22-23 - "So Moses returned to the Lord and said, 'Lord, why have You brought trouble on this people? Why is it You have sent me? For since I came to Pharaoh to speak in Your name, he has done evil to this people; neither have You delivered Your people at all.'" Sounds pretty bad, doesn't it? Here's Moses doing what God had called him to do and finding "no success" in his work, not seeing God answer prayer, and even having the people of Israel thoroughly upset with him. He really felt he had made a mistake and God shouldn't have sent him. He wasn't up to the task.
Umm, what did Moses think? He wasn't "up to the task?" Dr. Cook used this illustration to remind us that God calls us to serve Him but He doesn't call us to do so in our own strength. He actually uses our calling to show us we are nothing! He wants us not to rely on our own selves to accomplish God's work. Note, it's God's work, not ours.
Exodus 6:1 - "Then the Lord said to Moses, 'Now you will see what I will do.'" What was Moses going to see? He wouldn't see what he could do. He would see what God could do. He was learning to be "a nothing" and to see that God's work is all about God, not Moses. And Dr. Cook wanted us to see that our future ministries were not about us doing God's work, but God doing God's work through us, we who were nothing to ourselves so God could be seen as the source of power in our lives.
Note John 15:5 and Philippians 4:13. The first passage says, "...for without Me you can do nothing." The second passage says, "I can do all things through Christ who strengthens me." It's not me working for God. It's God working through me. I am a nothing - God is everything. And that is one of the important lessons of discipleship.