"Peace is not the absence of war." Spinoza said it, but it is mindlessly quoted out of context, for he added, "It is a virtue, a state of mind, a disposition for benevolence, confidence, justice."
The acquirement of spiritual wisdom does not necessarily prevent us from making worldly mistakes; but because it develops the qualities that will prevent them, and because it takes to heart the lessons of experience, humbly and receptively, it does reduce the frequency of those mistakes.