What is the ruling on marrying a Muslim woman who does not wear a hijab, while fearing that she will persist in this, and what sin would the husband incur in this case?

A righteous wife is the foundation of a upright family, and marriage to a religious woman is a prophetic injunction. We do not advise marrying a non-religious woman unless she desires guidance and seeks help. If the wife is non-religious after marriage, the husband must advise her, and if she insists on wrongdoing, he must divorce her.