One of the devil's weapons against us is intimidation. He will build an environment of instilling fear in us to doubt God's power. A case that exactly happenned to Moses. He will exaggerate our weaknesses to be our inability to obey God. For Moses, it was his stammering tongue. God will use you inspite of how imperfect others may consider you. The question would be, why do we have to pass through difficult times yet we have a caring God? Jesus never promised an un challenging christian life, he said in John 16:33, In the world you will face tribulations, but be of good cheer that I have overcome the world. He says in Mark 10:29, that those that have left everything for him and the gospel, he will give 100 fold with persecutions in this world and in the world eternal.