3 signs from The Load, go and do it; God will help us

Exodus 4:1-17
Moses has staff, God uses his staff in his life, God let Moses perform miraculous signs with it.
Moses afraid Israelites do not believe what he say, asked The Load gave him some signs.
The Load gave Moses 3 signs, 1)His staff can become a snake, 2) He can be leprous when he put his hand into his cloak. 3) He take some water from the Nile and pour it one the dry ground. The water he take from the river will become blood in the ground.
Moses was afraid he have never been eloquent, neither God have spoken to him, He was slow of speech and tongue.
The Load said: Who gave man his month?...Is it not I, The Load. Now go; I will help you speak adn will teach you what to say"
But Moses said,'O Load, please send someone else to do it", Then the Load's anger burned against Moses. God let hos brother Allen speak to the people for him. It will be as if he were Moses's mouth and as if Moses were God to Allen. The relationship between Moses and his brother Allen.
Why?
God used Moses's staff to be a sign, it was Moses living tool in his work everyday.
God give his servant many signs, at least 3 signs, let him know this is really came from the Load. It is not accident or magic.
Moses still doubt his speech, he afraid what he say in front of Israelites and Pharaoh. God gave him the faith even arrange his brother Allen to be his mouth. But Allen will as if Moses were God to him. Moses 's identity is most higher than his brother even Allen speech for Moses. The authority from the Load is not changed.
The Load gave Moses so many signs and said God will help him what to say, Moses had not faith so God angry to him.
God did not allow someone else replace Moses to be his servant
How?
Do not refuse God's sign and mission, Do not afraid what to say and what to do, if it is commanded from the Load, God is with me. Do not afraid about it. Just go and do it.
God will use what I familiar with it, God let us learned and prepared the mission for a long time when it is the time, God will let us to do it.
I may ask 3 signs to God to make sure what is the way I can go? or to do it.