How can a young man's heart (23 years old) be revived after its death to obedience to Allah, and how can he definitively abandon evil deeds and forbidden things?

Hearts are of three types: sound, sick, and dead. To treat a sick heart, one must eliminate the causes of its illness by sincere repentance from innovations and sins, nourish it with faith and acts of obedience, and protect it by frequent seeking of forgiveness. Among the most important causes for the life of the heart are: diligently contemplating the Book of Allah and pondering its verses, frequent remembrance of Allah, seeking beneficial knowledge, supplication, and choosing righteous companionship. Striving in this leads to the rectification of the heart, faith, and piety.