Does Allah accept the repentance of disobedient Muslims who repeatedly commit sins? And is the replacement of bad deeds with good deeds exclusive to polytheists if they embrace Islam, or does it include sinful Muslims? And how does a person repent and remain steadfast in repentance?

The Hadith of 'Ubadah applies to those who die persisting in sin. As for the repentant, Allah accepts their repentance, just as Allah forgives shirk for those who abandon it. Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" And the Prophet, peace and blessings be upon him, said: "The one who repents from sin is like one who has no sin." The transformation of bad deeds into good deeds is not exclusive to polytheists, and this is indicated by the Hadith of Abu Dharr, may Allah be pleased with him. And whoever sins and repents, then returns to sin, should not despair of Allah's mercy, and must repeat repentance with sincerity and devotion. Among the things that help in remaining steadfast in repentance are: striving in supplication, remembrance of Allah, being mindful of Him, remembering death, and keeping company with the righteous.