So He created night and day, motion and stillness, joy and sadness all of that due to the need of the created beings for it, to guide them to His Oneness.

For if He had not created the night, they would not have known the calculation of years and months, and the day would have been eternal upon them, and they would not have known a number for the years. And if He had not created stillness, motion would not be known, because the definition of motion is the absence of stillness, and the definition of stillness is the absence of motion. And likewise, joy and sadness run this course; things are created, and their opposites are created due to the need of the created beings. And likewise, were it not for denial, acknowledgment would not be known, and were it not for disobedience, obedience would not be known.

In summary, I say: Indeed, [regarding] the possessors of obedience and disobedience, He made them capable [of choice], and He did not compel them to anything, nor did He decree anything upon them [forcing their actions]. Glory be to Him and Exalted is He above what they associate [with Him].