When a person spends his entire day with no other concern but Allah alone, Allah, 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, Allah 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 Allah towards the love of some created being, cause his tongue to speak only in remembrance of that creation instead of remembering Allah, and cause his faculties to work in obeying and serving them. So he will strive hard, labouring like some work-animal, to serve something other than Allah.