An obligatory prerequisite in selecting a couple is that the couple is of your choice and is as much as possibile similar to you. This matter is undelined in Quranic Verses and traditions, both. “Being matched “ is an issue discussed in the book “ The structure of Family in Islam” by professor Hossein Ansarian.
Being Matched
Now that we have introduced the necessity of religion and piety, it should be noted that one of the most important conditions for marriage is that the couple should be well-matched. What is meant by being well-matched is that the couple who wish to get married must have some outward and inward similarities. The most important similarity is in their piety. That is according to the holy divine culture, they must both be religious. As the Holy Quran states:
And women of purity are for men of purity. [Holy Quran: Nur 24:26]
God's book states:
Marry women of your choice. [Holy Quran: Nisaa 4:3]
The first stage of this purity of men and women is their inward purity, that is, belief in God, the Hereafter, the Prophethood, the Quran, the angels and having divine morality. Therefore a believing Muslim man does not have the right to marry non-Muslim, unbelieving women. If such a forbidden marriage takes place, then their children are considered to be born in sin. In the same manner a Muslim believing woman does not have the right to marry an unbelieving man, and their marriage is considered illegitimate, as are their children. Believing men or women are not matched with unbelieving men or women. Should such a forbidden marriage take place, both sides are exposed to Eternal Torture.
The Glorious Quran has seriously advised against the marriage of a believing person with an unbeliever:
Do not marry unbelieving women (idolaters), until they believe: a slave woman who believes is better than an unbelieving woman, even though she allure you. Nor marry (your girls) to unbelievers until they believe: a man slave who believes is better then an unbeliever, even though he allure you. Unbelievers do (but) beckon you to the fire. But God beckons by His Grace to the Garden (of Bliss) and forgiveness, and makes His signs clear to mankind: that they may celebrate His praise. [Holy Quran: Baqara 2:221]
Therefore you must be careful not to let your believing daughters marry with a young fellow who is ignorant and does not have faith. Likewise, do not choose a girl who denies divine principles to marry your believing noble son. The first and foremost condition for the marriage of a couple is their faith. Thus two believing, chaste, and shining lights will join, the fruit of which will be good children. Do not think that being handsome, wealthy or of a high status for an unbelieving man, or likewise in a woman who is not adorned with the truth can bring prosperity, health, happiness and continuity of a mutual life. It is necessary for the families not to be too strict about finding the best match. When the two sides are nearly matched in terms of faith, morality and Islamic practices, and looks and posture, then they are considered to be a good match for each other by the Holy Shariat. Consider the following traditions regarding being matched:
Imam Sadiq (Pbuh) said: A woman who is chaste and is financially easy to live with is your best match. [Bihar al-Anwar, v.100, p.372]
The Prophet (Pbuh) said: If a courter proposes to marry your daughter and you are sure about his religiousness and trustworthiness, then provide the means for such a marriage. Prohibiting marriage of a well-matched couple may lead to sedition and great corruption on the Earth. [Ibid]
In another tradition the Prophet (Pbuh) said: Marry your daughter off to one whose morality and religiousness satisfies you. Should you prevent such a marriage, you have caused a great corruption and sedition on the Earth. [Bihar al-Anwar, v.100, p.373]
Yes, in fact the cause of self satisfaction, homosexuality, fornication, nervous problems, and psychic ailments of many young men and women is being too strict in regards to marriage; creating obstacles; insisting on wrong customs and traditions followed by imposing hard conditions; and expecting beauty, position and wealth by the families. And in fact the end results of all this will directly affect the parents, the relatives and those families who are too strict in regards to marriage, both here and in the Hereafter.
The Prophet (Pbuh) said: Provide the means for the wedding of well-matched couples. And marry with people who are a good match for you, and prepare them to marry you to bring forth good children. [Bihar al-Anwar, v.100, p.375]
The essential ingredients of a well-matched couple are faith, morality, trustworthiness and righteousness. It is the moral duty of the parents and the family to prepare the grounds for the marriage of a well-matched couple. This can be speeded up by being more lenient, not imposing ungodly conditions and avoiding unethical traditions. In this way the parents and the family can earn the blessings, pleasure and kindness of God.
Imam Baqir (Pbuh) said:
The greatest tragedy is when a young believing man proposes marriage to your daughter and you respond in the negative because he does not have the same financial status as you do. [Marriage in Islam, p.32]
Prejudices related to the family, city or tribe should be considered detrimental in marriage as such prejudices are rejected in the divine religion. So do not consider being poor or rich; coming from this city or that one; belonging to this tribe or that one as the criteria for marriage. All men and women are the offspring of one couple (Adam and Eve) and no one has any especial privileges over others except that due to being more pious and virtuous.
Imam Sajjad's Views on Being Matched
Hazrat Baqir (Pbuh), the fifth Imam said: In one of the way-stations during Hajj, my noble father Imam Zayn al-Abideen (Pbuh) encountered a lady whose good temper attracted him. He inquired if she was married, and was told that she was not. Then my father proposed to marry her without investigating about her family, and this proposal led to marriage.
One of the Ansar who became informed of this issue could not stand this simple marriage. He thought that she may not belong to a noble family, and this may cause problems for the fourth Imam. He spent some time investigating about her and finally found out that she belonged to the Shayban tribe. He came to the fourth Imam and told him that thanks God she is from a well-known, noble family. The Imam told him that he thought the man was wiser than that. He told him "Do you not know that God the Almighty removed all inferiorities and compensated for all defects by Islam. He replaced inferiority with nobility. Now, no matter what the social status of a Muslim is, he/she is not inferior but is respectable. The inferiorities belong to the Age of Ignorance."[Bihar al-Anwar, v.100, p.374]
Therefore being of the same tribe, dwelling in the same town or having the same amount of wealth do not mean being well-matched. As decreed by Islam there exist no privileges for the Arabs over the Persians; the whites over the blacks; the Qurayshy over the non-Qurayshy. All that counts is piety. If a Muslim couple have faith, piety, morality, trustworthiness, chastity, purity and health, then they are well-matched. This is true even if one is an Arab and the other one is a Persian; one lives in a city and the other one is a villager; one is rich and the other is poor; one is white and the other is black; one belongs to a noble family and the other one does not.
Ali, the son of Isbat wrote a letter to Imam Javad (Pbuh) and stated that he had not been able to find people that match him in faith and morality to marry off his daughters to. The Imam responded by writing: "I realized what you wrote regarding your daughters. May God bless you with His Mercy and Kindness. You need not be so careful in regards to your daughters. The Prophet (Pbuh) has recommended us to accept a courter's proposal to marry our daughters should his morality and religiousness be acceptable. Else sedition and great corruption would occur on Earth." [Bihar al-Anwar, v.100, p.373]
Imam Sadiq (Pbuh) told a man called Abraham: "No believer has ever gained any profit more dangerous than wealth. The danger of wealth is worse than that of two vicious wolves which attack a flock of sheep lacking a shepherd. What do these wolves do with the sheep?" He answered: "Nothing but a great loss." The Imam said: "That is right. The least danger of wealth is that a Muslim might come to propose to marry your daughter and you reject him for not being wealthy."
source : the structure of family in Islam