Is there any religious prohibition in the phrase: "If one of us knew what would come to him from the unseen, he would have avoided problems before their harm befell him"?

This statement is correct and consistent with the Muslim creed. Its meaning is that if a person were to know the unseen, they would avoid evils and increase in good. This intellectual premise demonstrates human weakness, helplessness, and submission to destiny. It is supported by the Almighty's saying: (Say, "I hold no power [even] for myself, neither to benefit nor to harm, except what Allah wills. And if I had known the unseen, I would have acquired much good, and no evil would have touched me. I am none but a warner and a bringer of good tidings to a people who believe.")