Marriage: Purpose and Obligation

Definition of Marriage
Nikah is an Arabic term used for marriage. It means "contract". ("Aqd in Arabic). The Quran specifically refers to marriage as "mithaqun Ghalithun,". Which means "a strong covenant".

"and they have taken a strong pledge (Mithaqun Ghalithun) from you?" (Quran 4:21)
The seriousness of this covenant becomes obvious when one finds the same term i.e., Mithaqun Ghalithun, being used for the covenant made between Allah and the Prophet before granting them the responsibility of the Prophethood. (Quran 33:7)

The Quran also uses the Arabic word "Hisn", suggesting "fortress" for marriage. Marriage is considered the fortress of chastity.

The Purpose of Marriage
As a meaningful institution, marriage has two main purposes:

To ensure preservation of the human species and continuation of the human race,

"O mankind! Be careful of your duty to your Lord, Who created you from a single soul and from it created its mate and from them has spread abroad a multitude of men and women" (Quran: 4:1)
To provide spiritual and legal foundation of the family

"And of His signs is this: He created for you mates from yourself that you might find rest in them, and He ordained between you love and mercy. Lo, therein indeed are portents for folk who reflect". (Quran 30:21)
Through Marriage, the conjugal relationship between a man and a woman becomes lawful. It provides a legitimate outlet for recreation as well as procreation. Islam regards sex as natural and good, but restricts it to the partners of marriage so as to ensure the responsibility for its consequences.

"Your women are a tilth for you so go to your tilth as you will, and send (good deeds) before you for your souls, and fear Allah, and know that you will (one day) meet him. Give glad tidings to believers, (O Muhammad)." (Quran 2:223)
Marriage provides spiritual, physical, emotional and psychological companionship. This companionship generates and sustains love, kindness, compassion, mutual confidence, solace and succor (sakinah). It lays a spiritual and legal foundation for raising a family. The children born of the matrimonial union become legitimate and mutual rights of inheritance are established.

Marriage: A Religious Requirement
Marriage in Islam is a recommended as a religious requirement.

"Marry those among you who are single and (marry) your slaves, male and female, that are righteous" (Quran 24:32)
Prophet Muhammad (S) declared:

"When the servant of Allah marries, he has fulfilled half the (responsibilities laid on him by the) faith; so let him be God conscious with respect to the other half". (Mishkat)
Marriage has also been commended as the way of the prophets.

"We indeed sent messengers before you (O Muhammad), and We assigned them wives and children" (Quran 13:38)
Marriage, in fact, is specifically considered the tradition (sunnah) of Prophet Muhammad (S) when he declared:

"Marriage is my Sunnah, whoever disregards my (sunnah) path is not from among us". (ibn Majah)
Islam discourages celibacy and encourages marriage, as Prophet Muhammad (S) recommended:

"Whoever is able to marry, should marry". (Bukhari)