What are the convincing and beneficial means that a student of knowledge or a preacher can use to instill faith in hardened hearts, awaken the greatness of God within them, and make them love religion, in order to achieve positive results in their call to righteousness and commitment?

The hearts of people are vessels for either good or corruption. Between these are hesitant hearts that need remembrance and admonition. The pieces of advice for inviting a heedless Muslim include good character and patience, opening the door of hope by speaking of the vastness of Allah's mercy, softening hardened hearts by coming to know Allah and His Names, Attributes, and blessings, motivating them to recite and ponder the Quran, inviting them to reflect on Allah's cosmic signs and their blessings, clarifying the obligation of showing gratitude for blessings, protecting their fleeting thoughts from the whispers of Satan and resisting desires, teaching them the love of obedience and the hatred of disobedience, teaching them matters of religion and general etiquette, turning hearts away from being distant from Allah, comforting them through encouragement and frightening them through deterrence, encouraging the companionship of righteous people and deterring the companionship of corrupt people, softening hearts with gentle admonition then stern, and always opening the door of hope. The essence of the matter is the striving of souls to constantly feel at ease with the words of Allah and the words of His Prophet, and to study the Quran and Sunnah.