What is the ruling on marrying a non-Muslim person who agreed to embrace Islam, pray, and fast for the sake of marriage, but without faith and conviction?

If a man declares that he will embrace Islam without faith or conviction, then his conversion is not valid, and it is impermissible to marry him. This is because he has not fulfilled the condition of certainty, which negates doubt, and he has not truly entered Islam. Allah Almighty says: "And do not marry polytheistic women until they believe." There has been a warning against the danger of feigning conversion to Islam for the purpose of marrying a Muslim woman.