I am not putting the blame towards Allah, what I meant was, maybe I questioned for too long/too much so now he realizes I am not worthy and put the seal like it says in the Quran.

Why to put the burden towards Allah?

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Nay, , but the fact of the matter is that what they earn has rusted/coated their hearts .

Surat-83

But one has still the option if one listens to the Messenger Sal'lallaa'hoalaih'wa'salam;

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You, the Messenger, pronounce universally and declaratively, "O my those servants who have done excesses to their selves; you people should not loose hope for the Mercy of Allah ;
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it is a fact that Allah forgives the slanders and sins , all collectively.
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Indeed He is the One Who is repeatedly Forgiving/Overlooking and the Fountain of Infinite Mercy.

Read conditionalities

Surat Az-Zumar-39

Thank you for providing the ayah.

Maybe everyone goes through the phases but for me it has been 2 years now, I think I am one of the ones whom Allah has placed "a seal on their hearts"

Some months ago I remember reading a translation of a verse that said those who believe, then don't believe, then believe again are the worst of all people and cursed.

Does anyone know what I am talking about?

It is very terrifying to me as I am struggling in a similar manner but I don't mean to be evil or bad -[