It was narrated that Anas (may Allaah be pleased with him) said: The Prophet (peace and blessings of Allaah be upon him) said: “Whoever is mainly concerned about the Hereafter, Allaah will make him feel independent of others and will make him focused and content, and his worldly affairs will fall into place. But whoever is mainly concerned with this world, Allaah will make him feel in constant need of others and will make him distracted and unfocused, and he will get nothing of this world except what is decreed for him.”

(Narrated by al-Tirmidhi, 2389; classed as saheeh by Shaykh al-Albaani in Saheeh al-Jaami’, 6510).

Ibn al-Qayyim (may Allaah have mercy on him) said: “When a person spends his entire day with no other concern but Allaah alone, Allaah, may He be glorified, will take care of all his needs and take care of all that is worrying him; He will empty his heart so that it will be filled only with love for Him, free his tongue so that it will speak only in remembrance of Him (dhikr) and cause all his faculties to work only in obedience to Him. But if a person spends his entire day with no other concern but this world, Allaah will make him bear its distress, anxiety and pain; He will leave him to sort himself out, and cause his heart to be distracted from the love of Allaah towards the love of some created being, cause his tongue to speak only in remembering people instead of remembering Allaah, and cause him to use his talents and energy in obeying and serving them. So he will strive hard, labouring like some work-animal, to serve something other than Allaah… Everyone who turns away from being a true slave of Allaah and obeying Him and loving Him will be burdened with servitude, love and obedience to some created being. Allaah says (interpretation of the meaning): ‘And whosoever turns away (blinds himself) from the remembrance of the Most Beneficent (Allaah), We appoint for him a shaytaan (devil) to be a qareen (intimate companion) to him.’ [al-Zukhruf 43:36].”
Al-Fawaa’id, p. 159