How does a person achieve inner peace?

A Muslim achieves psychological comfort through faith, righteous deeds, avoiding disbelief and sins, accompanying the righteous, attending circles of knowledge, dedicating their efforts to the Hereafter, and rising above worldly concerns. The Prophet, peace and blessings be upon him, said: "Whoever makes all worries one worry, the worry of his Hereafter, Allah will suffice him for the worries of his worldly life. And whoever is distracted by worries in the affairs of this world, Allah will not care in which of its valleys he perishes." He also said: "Whoever has the Hereafter as his main concern, Allah will place richness in his heart, gather his affairs for him, and the world will come to him submissively. And whoever has the world as his main concern, Allah will place poverty before his eyes, scatter his affairs, and nothing will come to him from the world except what has been decreed for him."