There is a vast difference between wanting to and willingness.
I believe Moses wanted to do as God requested and speak to Pharaoh in releasing the children of Israel. However, he had the "paralysis of analysis" and the fear in himself talked him out of his anointing. He told God in Exodus 4:13, "O Lord, please send someone else to do it." Have you ever found yourself pulling a Moses on God? In your heart, you WANT to do what He's telling you to do, but you've found enough excuses that you're not WILLING to do what He's telling you to do. Meantime, Aaron's willingness was stronger than his want to.
Exodus 4:30 gives another glimpse into this. Moses and Aaron gathered all of the elders of the Israelites together: "...and Aaron told them everything the Lord had said to Moses." Notice who was willing to speak.
Because Aaron was willing, he threw his staff down on the ground before Pharaoh and God turned it into a snake which swallowed up the staffs of the wise men and sorcerers in Pharaoh's court. God saw how Aaron was willing while Moses only gave excuses. So in Exodus 7:19, God says to Moses "Tell Aaron.." Exodus 8:5, God says to Moses "Tell Aaron..." In Exodus 8:16, God says to Moses "Tell Aaron.." Are you getting my point? God knew who would join Him in His work and who would only want to do it.
But something begins to happen to Moses in all of this. He begins to see how God doesn't call the qualified but qualifies the called. Because Moses if'ed and but'ed his way out of his anointing at the time God needed him the most, Moses saw how God used Aaron to perform miracles that were initially meant for Moses!
Moses' "want to" had turned to him being willing to act. In watching all that God had done through Aaron, his faith in God had grown. While the children of Israel were at a dead end with the Red Sea facing them and the mountains of Egypt to their backs, Moses came face to face with the spirit of intimidation that had paralyzed him long enough. God asked Moses in Exodus 14:15-16, "'Why are you crying out to me? Tell the Israelites to move on. Raise your staff and stretch out your hand over the sea to divide the water so that the Israelites can go through the sea on dry ground.'" Moses could either grab Aaron and say, "Here! You've done this before. God turned your staff into a snake in front of Pharaoh! Do SOMETHING!" But he didn't.
God never intended for Aaron to lift up his staff at the Red Sea. God wanted Moses. Moses had been encouraged by what he had seen Aaron do. Moses had learned to let God encourage his heart.
God's promises are contingent upon your obedience to what He's called you to do.
(Barbie will be the guest speaker at the Univeristy of Mississippi Medical Center's Hospital Week forum Tuesday, May 8.)