How can a girl overcome her anxieties and fears about her future husband marrying another, knowing that some scholars believe fulfilling conditions is not obligatory, and what is the legitimate way to make the condition of him not marrying another binding upon her husband, from which he cannot escape?

Marriage involves great legitimate objectives, such as chastity and procreation, and it has many benefits, including repelling the evils of lust. It is also a cause for two lives, one perishable and one lasting, and it fulfills God's will for the continuation of the human species, an obedience to the command of the Messenger of Allah, peace and blessings be upon him, and a means for the continuation of one's legacy and elevation of one's status through the supplication of a righteous child. Therefore, anxieties should not be an impediment to it. And even if a husband were to marry another woman, it does not necessarily lead to the failure of the marital life. There must be a good choice from the outset, so one should seek a competent husband who possesses good character and religious commitment, as stated in the hadith, "If there comes to you one whose character and religious commitment you are pleased with, then marry him." Along with good choice and consultation, seeking guidance (istikharah) is among the means of attaining success. Life's purity may not be entirely free from blemish, and the sound principle is to tolerate minor harms in order to achieve major benefits. Marriage may even be obligatory for someone who fears falling into temptation.