Is there a willingness to listen to God?

Read Exodus 3.

Another 40 years went by.  Moses was now 80.  In humility, he spent the middle part of his life tending the sheep of his father-in-law.  God used this time to change Moses' character and to teach him how to lead a flock in the desert.

God revealed Himself in a creative way, using a curiosity approach to get Moses' attention.  It was not until Moses "turned aside to see" that God spoke to him.  Hearing what God has to say begins with a willingness to turn to Him.  Once a person becomes willing then God can get His message through to them.

Now, that God has Moses' attention and willingness, He unfolds the deliverance plan for the people of Israel.  When God wants something done, He will give the vision for the task to a leader of His choosing.  Moses was to be that leader.

Notice that Moses had lost his swagger and confidence.  Then, he began questioning and pushing back on God's call for his life.  When a person has been hurt, rejected and disillusioned, their focus is on self and self-protection.  Each time God gave him all that would be needed for success.

Moses: "Who am I?"
God: "I will be with you" and then God added a specific promise of deliverance.
The issue was no longer the call, but Moses' faith in the living God.

Moses: "What is his name?" 
God: "I AM who I AM."
Moses envisioned that he would be rejected by the people as having no authority to deliver God's message to them and lead.  Again, his focus is on self, rather than the person and power of God.  The "I AM" refers to God's eternal nature.  He is always in the present tense as the self-existent One.  Compare the I AM statements of Jesus in the Gospels.  The indication is that God would prepare the people to recognize that name as authoritative and follow Moses.  And, again, God added the promise of deliverance.

One by one, the LORD supplied a solid answer to each of Moses' questions.  It is more than okay, it is good for humans to ask questions concerning their faith and God's Word.  But after one knows what God has said, then it falls on human responsibility to obey immediately.