How can one remain steadfast in obedience and know Allah's pleasure and acceptance of a servant's repentance, despite the existence of other sins?

Steadfastness in obedience refers to previous fatwas. As for the signs of Allah's love for a servant and His pleasure with them, they are the servant's love for Allah and following the Prophet, peace and blessings be upon him, and being characterized by the qualities mentioned in the Quran, such as "humble towards the believers, firm against the disbelievers, striving in the way of Allah, and not fearing the blame of any blamer." Other signs include being afflicted with calamities accompanied by patience, Allah taking charge of the servant's affairs outwardly and inwardly until their limbs are guided to what pleases Allah, and being loved and accepted by people. These signs are general, and it is not possible to definitively state Allah's love for a specific servant because that is part of the Unseen.

As for the acceptance of repentance from one sin while persisting in another, there are two opinions among scholars: some prohibited it, while the majority considered it valid. Ibn al-Qayyim took a middle ground, stating that repentance is not valid for a sin while persisting in another sin of the same type, but it is valid for a sin while persisting in another sin that is not related to it or is not of the same type. Delaying repentance is also a sin that necessitates repentance; therefore, repentance is obligatory for all sins.