Translation:

179. Allah will not leave the believers in the state in which ye are now until He separates what is evil from what is good. Nor will He disclose to you the secrets of the Unseen. But He chooses of his Apostles (for the purpose) whom He pleases. So believe in Allah and His Apostles: and if ye believe and do right ye have a reward without measure.

Notes (Tafseer)

481. The testing of good men by calamities and evil men by leaving them in the enjoyment of good things is part of the trials of Allah, in which some freedom of choice is left to man. The psychological and subjective test is unfailing, and the separation is effected partly by the operation of the human wills, to which some freedom is allowed. But it must be effected, if only in the interests of the good.

482. Man in his weak state would be most miserable if he could see the secrets of the Future or the secrets of the Unseen. But things are revealed to him from time to time as may be expedient for him, by Messengers chosen for the purpose. Our duty is to hold fast by faith and lead a good life.