There is a common theme running from the Book of Genesis through the book of The Revelation. That is, God invites people into His presence (God's MERCY), they refuse, and they are subsequently banished from God’s presence (God's WRATH).
For example, Adam and Eve could have eaten from the tree of life and lived forever in God’s presence (Genesis 3:22). Instead, they refused, ate from the Tree of the Knowledge of Good and Evil and were banished from the Garden of Eden, the Garden of God, where God walked with them (Genesis 3:8,23,24).
Israel is invited to be with God at Mount Sinai. They refused by running from God and this rebellion ultimately resulted in their banishment and subsequent death in the wilderness. (Exodus 19:16-19; 20:18-21)
God invites the children of Israel to recognize Him as their King. Israel refuses to recognize God as their king and rather chooses a human king (1 Samuel 8:6,7). This ultimately leads to sin and the banishment from God of the whole nation of Israel! (Jeremiah 3:8)
Jesus tells us the same story with a twist – others will be invited to take the place of those banished (cf. Romans 11:17-20).
Juxtaposed to the unjust judge in this parable or story, our God is a just judge and certainly will do much better than any human judge (Isaiah 45:21,22). Again, the point of this parable is if an unjust human judge will give you what you want just to stop the constant asking will not a God that is grace, mercy-love, and compassion answer your request quickly? (Jeremiah 29:12,13. Psalms 103:13,14. Isaiah 42:3,4) The conclusion - we are not to give up on our requests to God in prayer (1) even if the answer seems to us delayed! (Isaiah 64:4)
Similar to the unjust judge being used to teach us about our just God, King Ahasuerus is used to illustrate the dealings of God with Israel. Ahasuerus is king of the world and treats his subjects, including his wife, to blessings and liberty without end (Esther 1:1-4). Then he invites her to his presence – she refuses and is banished (Esther 1:11,12,19). I believe Vashti represents the nation of Israel who refused to come into God’s presence. Israel is banished. I believe Esther represents the church that is chosen to take Israel's place during this age. She is treated with the King’s oil (the anointing of the Holy Spirit) and perfume (representing obedience through death to self). She only wants what Hegai (her helper, guide, coach, etc. representing the Holy Spirit) tells her to do, say, or be in the King's presence. She becomes the bride without spot or wrinkle (Ephesians 5:27).
Do not ever forget, God's MERCY rejected leaves only God's WRATH (Hebrews 10:30,31).
Furthermore, do not mistake the patience of God against sin as His affirmation and acceptance of it. (Numbers 14:18. Romans 9:22. 2 Peter 3:9. Ecclesiastes 8:11)
MERCY (1), Today is the day of salvation! (2 Corinthians 6:2) All that repent and confess their sins shall be forgiven and saved! (Romans 10:9-13)
WRATH (1) All that fail to repent will be banished.
SELAH (Pause and reflect on this)