All praise is due to Allah, the Master of the Heaven and the Earth. O Allah! Send peace on Muhammad and his holy family.
Before we begin our discussion on the merits of Mutah marriage, we must first make a distinction between the Islamic law and the actions of man. For example in the contract of Nikah marriage, Islam gives the husband rights over the wife, and the wife over the husband. If the husband decides to oppress the wife, do we blame the contract of Nikah marriage? The answer is clearly no. The fault, blame and sin lies with the oppressing husband. The same principle can be applied to the contract of Mutah marriage. Any malpractice is due to the lack of taqwa (piety) of the people (or person) involved and not because of the existence of Mutah marriage as an institution.
In respect to the merits of Mutah marriage - it's like the merits of other acts of mu'amalat and ibadat (transactions and worship respectively). They all lead to developing the characteristics of the true mu'mineen (believers). From my understanding of Islam, all laws of Allah are positive and beneficial. They all lead to increasing one's levels of spirituality. Even Mutah marriage! Remember, Islam does not see the relationship between male and female (husband and wife) as something evil and disgusting, but something natural and positive. As human beings have been given procreative instincts, it is in their nature to desire the company of the opposite sex (this may or may not entail physical intercourse). Now, if the situation arrives where permanent Nikah marriage cannot solve the problem, the individual has two options. The first is to remain single. In a number of cases this is fine, because some individuals will be able to control their own instincts. In other cases where the procreation instinct is stronger it is not possible for them to remain single without falling into sin. In this case, Mutah marriage can save them from sin and also should be able to lead to higher level of taqwa.
Another benefit of Mutah marriage is its ability to solve the problems related to the engagement period. During the engagement the couple are still na-mahram to each other (they are still obliged to abide by the rules of Hijab). Thus what they can talk about and where they can meet is limited. However by entering into a Mutah contract the couple can avoid any unintentional sin caused by being engaged.
Islam came as a system of life to govern all the actions of society - be it political, social, economic or judicial. Within the social system we have the concept of segregation of the sexes and Hijab. Allah (S.W.T.) ordained that na-mahram (anyone with whom marriage is potentially possible according to Islamic law) males and females should as an obligation maintain Hijab and have segregation between themselves. Islam for example limits the content of discussion between na-mahram males and females to certain issues, such as Islam and education. Idle talk between a na-mahram male and a na-mahram female is hence forbidden (and sinful). To be in a private place where there is a chance of sin being committed is also forbidden.
During my younger days whilst studying for my A' levels I became active in the Islamic arena. This meant I got involved in discussing Islam with Muslims and non-Muslims. Among those non-Muslims that I met, was a girl from the Ahle-Kitab - a Christian in this case. As she new who I was, because we were in the same class together, and there were no active or well-versed sisters (regardless of being Sunni or Shia), I began a discussion about Islam with her. At first I began to ask her questions to determine her level of understanding regarding man, life and the universe. Questions like: How did I get here? What am I here for in this life and what happens when I die? I then began to explain how Islam deals with these questions. Throughout this time I had to be very careful I did not over step the bounds of what the Shariah permits me to discuss because this would have led me to sin.
As my time at college came near to an end, I new it would no longer be viable to continue our discussion much longer. I had a discussion with her for one last time, reiterating the need to continue to search for the Truth and how to recognise the Truth once it is found. I said I would wait a period of five years before I met her again to discuss Islam further.
Over the next three years whilst studying for my degree, occasionally I would bump into her e.g. whilst I was shopping. After finishing my degree I decided to continue my studies for a further year to do a Masters degree. At the same time this girl decided to come and study at the same university I was at. She asked me if we could meet before the commencing of the academic year. When I agreed to meet, I decided, to ensure that I did not slip out of the boundaries of the Shariah, I would enter into a Mutah contract with her. Thus when I met the girl at university I explained to her the Islamic concept of Mutah marriage. She agreed to enter into a Mutah contract with me. The contract lasted for a period of one and a half hours. Within that period there was no physical contact and we didn't even look eye to eye (even though within the Mutah contract it was permissible to do so). Thus my objective for the Mutah contract was not to find a wife, but to assess the situation of the girl with more freedom. I entered into the Mutah contract because I was unsure about the type of conversation we would have. I wanted to ascertain her thoughts and ideas, but I didn't have any topic specifically prepared to discuss. This meant it would be very easy to sidetrack to discuss issues which Islam didn't permit me to discuss in such a situation (e.g. fashion). The contract of Mutah marriage allowed me to be in a situation that eliminated a number of sins, which could otherwise have arisen.