What must a Muslim do who has been disobedient to his parents, doubts matters of religion, and has committed some sins, in order to repent to Allah and expiate his sins, and what are the consequences for someone who has fallen into one of the ten nullifiers of Islam?

Allah has made it obligatory to honor one's parents, treat them with kindness, and show them reverence. He has forbidden disobedience to them, which is considered one of the major sins. It is obligatory to be kind to them and not to treat them harshly, while supplicating for their guidance and forgiveness. Lenience in religious matters and a lack of inner peace may be due to disobedience to parents. Therefore, one should hasten to repent, seek their رضا, and apologize to them. Honoring parents does not contradict enjoining good and forbidding evil to them, provided it is done with wisdom and good counsel. Sincere repentance atones for all the sins and transgressions that have been mentioned.