Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- The act of engaging in a romantic relationship with someone of the same gender is shameful, uncommon, and sinful.
2- Marriage to someone of the same gender is also invalid and prohibited.
3- A person who has an attraction to someone of the same gender is not sinful just for having those thoughts, as long as they do not act on them.
4- A Muslim is able to interact and associate with such people with no problem.
5- Muslims should never be part of an agenda to normalize something like homosexuality which is both prohibited and harmful to society.
Answering your question about same gender relations in Islam, Sheikh Mustafa Umar, President of California Islamic University, states:
What Is Homosexuality?
Homosexuality is the idea of feeling attracted to someone of the same gender and having a relationship with them. The Quran takes a clear position that homosexuality is both sinful and shameful. Allah says,
{And (We sent) Lut (Lot) when he said to his people, ‘Do you commit the shameful act in which nobody in the world has ever preceded you? You come to men lustfully instead of women. No, you are a people who cross the limits [of decency].’ The answer of his people was no other than to say, ‘Expel them from your town. They are a people who pretend too much purity.’} (Al-A`raf 7:80-82)
From the preceding verses, it is clear that the act of engaging in a romantic relationship with someone of the same gender is shameful, uncommon [no one preceded you as a society], and sinful [cross the limits Allah has set].
The language used in the verses critiquing homosexuality are not open for any other interpretation, which is why there has never been any scholar in history who tried to give a different spin to these verses.
Islam takes a strict stance against the practice of homosexuality because it is harmful to society, the same way that adultery and fornication is considered a major sin in Islam since it harms society through destruction of the family system.
Marriage to Someone of the Same gender
Since the act is clearly prohibited in Islam, it also results in an invalid marriage. A valid marriage is only between a man and a woman who are not close relatives to each other like a parent, sibling, child, or uncle/aunt. Likewise, marriage to someone of the same gender is also invalid and prohibited.
Islam differentiates between a person’s thoughts and their actions. Prophet Muhammad (peace be upon him) said, “Allah has forgiven my community for whatever crosses their mind so long as they do not speak of it or act upon it.” (Al-Bukhari and Muslim)
This means that a person who has an attraction to someone of the same gender is not sinful just for having those thoughts, as long as they do not act on them.
Therefore, Islam differentiates between Same Sex Attraction [SSA] and Homosexuality. The first one is the inclination or desire towards a person while the second one is actually trying to act on that desire and have a physical relationship with a person. The first is not sinful but the second one is.
From a purely scientific and psychological perspective, researchers admit they do not understand why a person has Same Sex Attraction in the first place. From an Islamic perspective, it does not matter.
Their abnormal desires for the same gender may be something they acquired from their upbringing or environment without any choice of their own, or may be a result of some habits or actions they did choose.
Either way, their desires are a test from Allah, the same way that many people are attracted to others whom they will never be able to marry.
How Should Muslim Deal with people involved in Same Gender Relationships
As for dealing with people who choose to act on their desires and engage openly in homosexuality, they are treated by Muslims like any other person committing a sin.
Among the things prohibited in Islam and harmful to society are drinking wine, fornication, adultery, dealing in interest, and gambling.
Yet, there are countless number of people that Muslims regularly interact with who do these things, and even justify them. A Muslim is able to interact and associate with such people with no problem. Associating with a person who is gay or lesbian is the same.
Muslims, however, must be cautious of the LGBT movement in Western countries. The movement claims to combat discrimination and bullying against homosexuals but often, in reality, it attempts to normalize homosexuality in society.
There is no benefit in mocking or bullying anyone who is gay or lesbian, and Muslims should aid in stopping such harassment.
However, Muslims should never be part of an agenda to normalize something like homosexuality which is both prohibited and harmful to society.
Often, under the banner of ‘gay rights’ or ‘combating discrimination’, several Muslims actually end up promoting homosexuality in their society, even if that promotion is only directed towards non-Muslims.
Such an effect is tantamount to promoting adultery and fornication, and helping to normalize and destigmatize it, even for non-Muslims.
Almighty Allah knows best.