Overall meaning : God forbids His believing servants from betraying Him and His Messenger by leaving what He commands and doing what He forbids, and from knowingly misappropriating anything that has been entrusted to them when they know that it is a trust that must be honoured.
Then He directs them to know that the worldly goods and children He has granted them are but a trial to see whether they will fulfil the obligations Allah has enjoined on them regarding them or let their love for them make them give their whims and desires precedence over keeping what He has entrusted them with, and that He has a tremendous reward in store for those who obey His commands.
He explains to them that if they fear Him by doing what He commands and avoiding what He forbids, He will grant them knowledge whereby they will be able to distinguish truth from falsehood, a way out of worldly distress, as well as victory and support, and will wipe away their misdeeds and forgive their sins, stating that His grace is unbounded.