There are no means of attaining faith and certainty except through the Qur'an.

Doom comes about because of neglecting to evaluate one's self and because of just following one's whims.

When there is money in your hand and not in your heart, it will not harm you even if it is a lot; and when it is in your heart, it will harm you even if there is none in your hands.

The sinner does not feel any remorse over his sins, that is because his heart is already dead

How is it possible for one’s heart to be certain that one is going to meet Allah, that Allah sees and hears all that he does, and knows his secret open affairs, and that he will be made to stand before Allah, answerable for all his deeds - how can one be certain and aware of all of this, and yet persist upon things which displease Allah; persist upon abandoning Allah’s orders, neglecting His rights, and yet claim that he has good expectation of Allah?

Whoever mocks his brother for a sin they repented from will not die till he himself falls into the same sin.

The keys to the life of the heart lie in reflecting upon the Quran, being humble before Allah in secret, and leaving sins.