Assaalamu 'alaykum.If a person beliefs in his heart, declares by tongue Shahadatyn, leaves all the nullifiers of faith but at the same time doesn't do any good deed in action. What is the stance of Ahlus sunnah wal Jamah about his faith?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The principle that Ahlus-Sunnah wal-Jamaa’ah adopt is that faith includes words and actions; words by the heart (belief), and words by the tongue; deeds by the heart and deeds by the limbs.

If there is any faith in the heart, then automatically the body reacts to that by doing all possible acts by the limbs. It is not imagined that a person would claim faith and yet abandons performing good actions with his limbs, this cannot be possible.

Shaykh Ibn Taymiyyah said:

"It is not possible that a man firmly believes in his heart that Allah ordained him to pray, pay Zakat, fast, and perform Hajj while he spends his entire life not prostrating once to Allah, not fasting the month of Ramadan, not paying the Zakat which Allah imposed on him, and not performing pilgrimage to the House of Allah. This is not possible, and it is a behavior of someone who has hypocrisy in his heart; this is not a behavior of someone who has true faith (in the heart).” [End of quote]

For more benefit, please refer to Fatwa 329314.

Allah knows best.