What is the ruling of the Shari'ah and what should I do regarding the suitor's father's refusal to complete the marriage, despite his prior approval and the desire of both parties, and based on the saying of the Messenger of Allah, peace and blessings be upon him: "If two people love each other, marry them"?

It is not permissible for a father to prevent his mature, sane son from marrying the woman he desires, provided she is of good character and religious. The son should advise his father regarding the importance of choosing a partner for the husband himself, citing the verse: "Then marry those that please you of [other] women" (Quran 4:3) and the Hadith: "Go and look at her, for it is more likely to engender affection between the two of you." If the father insists, it is better for the son to obey him, unless he would incur religious or worldly harm by abandoning this marriage. In such a case, he is permitted to marry without his father's consent, and he should then seek to appease his father later. As for the Hadith mentioned, it is: "There is nothing like marriage for those who love one another."