Even after finding out the truth that Islam is nothing except of the dramas of human revelation, still I was unable to take the FINAL step of leaving it and I had to stick with Islam for a couple of years more in this state. 

Especially, the last question was: "What if Allah appears after my death?"

I pondered upon this question from every angle and then addressed Allah the last time: 

"O Allah! If you really exist, and you also know what I have in my heart, then you can see that I did my best to seek out the truth.
And my honest search ultimately led me to this conclusion with the true depths of my heart that you don't exist.
And humanity within me guides only to this conclusion that your system (i.e. Islam) is based upon the enmity against the humanity.
Do you really want me to become a hypocrite and even if my heart and mind internally clearly deny your existence, but I should externally still keep on acknowledging your existence?
And if I refuse to act as a hypocrite, then you put me in eternal fire despite my true heart? And all the good deeds that I do for the sake of humanity, they go to waste and the final destination will be eternal fire?
So, if I have to answer my deed of not believing in you, then "first" you have to answer your deed of not providing enough proof of your existence. You have to answer why I was unable to recognize you despite my true search for you? You have to answer why billions of people have to burn in the eternal fire while you made them to born in the non-Muslim families and thus, they could not become Muslims?
If you deny my true intentions, then either your claim of إنما الأعمال بالنيات (Verily, the reward of deeds depends on the intentions) is false, or your promise of eternal hell is false. 

These were my last words to Allah. I never addressed him thereafter.

These words served as a "powerful argument" for me, and they encouraged me and helped me to take that last and final step of leaving Islam.

According to Islam, the way it works is that you learn about Islam enough that at some point, it resonates with you and you believe it to be true in your heart. And if that doesn't happen, it means Allah chose not to give you divine guidance, but it's your fault somehow, and you deserve to be punished in the worst way possible for eternity.

PS:

This question (i.e. what if God appears before your after your death) is popularly known as Pascal's wager. Pascal's wager, originally proposed by Blaise Pascal (1623–1662), takes a more pragmatic approach. Pascal thought that evidence cannot settle the question of whether God exists, so he proposes that you should bet, or wager, on God because of what's at stake: you have lots to gain and not much to lose.

Nevertheless, you can make a pascal's wager for everything. For example, even if you disagree with this post but still you have to praise it, or you will become ill next week. All it costs you is to praise it in your heart, so why take the risk? And don't forget to make your children praise it too! You don't want them to become ill, right?