To what extent does divine decree and destiny (Qada' and Qadar) influence human life, and is one predestined or given free choice in the varying abilities of children, the selection of a spouse, and the path of academic specialization and career?

"Humans are both predestined and given free will simultaneously. Matters occur by Allah's divine decree (qada') and preordainment (qadar), and in these, humans are predestined, as Allah Almighty ordained and wrote down everything before His creation. This is the meaning of being predestined. As for being given free will, it is because Allah Almighty granted humans the choice in what they witness and perceive. Their choice may or may not come to fruition according to what Allah has decreed, for Allah Almighty encompasses all things with His knowledge. Everything that happens on earth, whether intelligence or dullness, marriage or employment, is by Allah's divine decree and preordainment. Nevertheless, humans have choice and will in matters where they can choose, but there are innate matters that a servant does not choose. All of this has been decreed by Allah Almighty with His knowledge and wisdom."