And Allah Most High says:

“And among the people is he who worships Allah on an edge. If good befalls him, he is reassured by it; but if a trial befalls him, he turns away, losing both this world and the Hereafter. That is the manifest loss.”

Surah al-Hajj, 11.

He also says:

“Alif, Lām, Mīm. Do people think that they will be left to say, ‘We believe,’ without being tested? We certainly tested those before them, and Allah will surely make evident those who are truthful, and He will surely make evident the liars.”

The passage continues to His words:

“And among the people are those who say, ‘We believe in Allah,’ but when they are harmed for Allah’s sake, they regard persecution by people as though it were Allah’s punishment. Yet if victory comes from your Lord, they will surely say, ‘We were indeed with you.’ Does Allah not know best what is in the hearts of all people?”

Surah al-‘Ankabūt, 1–10.

He also says:

“Or do you think that you will enter Paradise before there has come upon you the like of what befell those who passed away before you?”

To the end of the verse. Surah al-Baqarah, 214.

He also says:

“Or do you think that you will enter Paradise before Allah has made evident those of you who strive and those who are steadfast?”

Surah Āl ‘Imrān, 142.

When mentioning apostasy—from which He exempted those who are coerced while their hearts remain firm in faith—He said:

“But those who open their hearts to disbelief will incur Allah’s wrath, and they will have a tremendous punishment. That is because they preferred the life of this world to the Hereafter, and because Allah does not guide the disbelieving people.”

Surah al-Nahl, 106.