Is repentance for some sins valid while persisting in other sins, and does longing for a sin after repentance affect the validity of that repentance?

Repentance from a sin is valid, even with persistence in another, according to the majority of scholars. Repentance is sound if a person refrains from disobedience out of obedience to Allah Almighty and seeking His pleasure. Umar ibn al-Khattab, may Allah be pleased with him, was asked which is better: a man who does not desire sin and does not commit it, or a man who desires sin but does not commit it? He replied that those who desire sin but do not commit it are those whose hearts Allah has tested for piety, and for them is forgiveness and a great reward. A person should strive to reach a high status of faith by continuously remembering Allah, seeking His help, and taking the means to increase faith.