What are the pieces of advice for restoring faith and strength after a period of doctrinal deviation, justifying adultery, and weakness of faith?

The knowledge of the Hour's advent is exclusive to Allah Almighty. A Muslim should not preoccupy himself with the timing of the Hour's establishment. Rather, he should remember the Hereafter and prepare for it by being steadfast in obedience, performing many good deeds, and repenting to Allah. Whoever claims to know the time of the Hour's advent has explicitly denied the Qur'an and is expelled from the fold of Islam. Permitting adultery is disbelief because whoever believes something to be lawful that is unanimously forbidden has committed disbelief. It is advised to repent to Allah, persevere in acts of obedience, seek religious knowledge, and associate with the righteous.