How can one achieve a sound heart that is loving and submissive to Allah?

Assisting in attaining a good opinion of Allah, relying on Him, and having a sound heart are several matters, the most important of which is constant contemplation of Allah’s Most Beautiful Names and Attributes. For instance, knowing the name "Al-Wakil" (The Disposer of Affairs) instills reliance upon Him, and knowing His Mercy and Forgiveness improves one's opinion of Him. Reflecting on the Holy Quran is among the greatest aids in this regard, for it introduces one to the Lord, blessed and exalted be He.

Ibn Al-Qayyim said: The Quran is the word of Allah and His manifestation to His servants. Sometimes it manifests through attributes of awe and grandeur, causing souls to submit. Sometimes through attributes of beauty and perfection, filling the heart with His love. Sometimes through attributes of mercy, inspiring hope. Sometimes through attributes of justice and punishment, suppressing the commanding self. Sometimes through attributes of command and prohibition, motivating compliance. Sometimes through attributes of hearing, sight, and knowledge, inspiring modesty. Sometimes through attributes of sufficiency, necessitating reliance. And sometimes through attributes of might and majesty, leading to humility and brokenness.

Allah the Exalted introduces Himself to His servant through the attributes of His Divinity (Uluhiyyah) and Lordship (Rububiyyah). The former necessitates His love and yearning for His meeting, while the latter necessitates reliance on Him and dependence on Him. The perfection of this is for the servant to witness His Lordship within His Divinity, and His Divinity within His Lordship. Reflecting on the Quran without distortion makes the servant witness a Self-Subsisting King Who manages the affairs of His servants, described with every perfection, and free from every flaw.