What is the ruling of the Shari’ah regarding a man who wishes to divorce his wife due to lack of understanding, and has abandoned her for a year and a half, knowing that his father refuses the divorce because he is an agent over his money and the wife is the daughter of his friend?

We advise you to be patient before divorcing, for Allah might reconcile you both. You can marry another while keeping the first and treating her kindly. Your father does not have the right to prevent you from marrying or disposing of your wealth as long as you are an adult of sound mind, but his approval is a form of righteousness. If you are able to be patient and address the issue, then do so. Otherwise, there is no blame upon you for divorcing, even if your father is not pleased with it.