Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
The true believers who die in a state of faith will be able to answer the three questions in the grave.
In responding to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
The true believers who die in a state of faith will be able to answer all the three questions put by the angels in the grave correctly. The angels will support them.
Allah says:
“Allah will strengthen or give firmness to those who believe in the firmly rooted word, both in this world and the Hereafter, but the evildoers He leaves to stray: Allah does whatever He will.” (Ibrahim 14:27)
This blessing will be extended at the time of interrogation by the angels. That is why Prophet Muhammad (peace be upon him) ordered us to pray to Allah to bestow firmness on the heart of a person after we have buried him or her.
In other words, the hearts of the believers will be firm when they are faced with questions from the angels in the grave. And thus, they would be able to answer the questions.
The lesson we learn from this is that we ought to strive hard to remain steadfast in the practice of Islam and pray to Allah to keep our hearts firm and save us from going astray and losing our faith.
One of the prayers of the Prophet was:
(O Allah, You are the twister and turner of hearts. Make my heart firm and steadfast on Your religion and the Truth.)
Almighty Allah knows best.