The story of Queen Esther can be viewed on a much broader scale when we transpose God and all of humanity in place of the king and queen, and Haman for Satan. When Esther was warned of the evil plot Haman had devised to destroy all the Jews, she asked that all her people fast and pray with her before she courageously sought an audience with the king.
Queen Esther was completely aware that she had replaced her predecessor (the deposed Queen Vashti) because of disobedience. Yet Esther chose to defy a potential death sentence, knowing she was not authorized to talk to King Xerxes unless she was personally summoned.
Similarly, we will never be granted permission to come boldly before the throne of God to plead for forgiveness from our wrongdoing and the ultimate death sentence that accompanies it, without first acknowledging (and accepting) the work of Jesus on the cross. Because of Jesus' propitiation for our sinful life, God freely extends His scepter of grace to all who ask, enthusiastically welcoming us into His presence. The Bible makes it clear that we cannot come into God's presence alone. We need the atoning work of Jesus Christ to be able to stand before a Holy God, in order to gain access to His mercy.