This is a major sin that led to the destruction of people of Loot (‘Alaihis salatu wassallam). They (gays and lesbians) both go against the natural disposition (fitrah) which Allaah has created in mankind – and also in animals – whereby the male is inclined towards the female, and vice versa.
Allaah says (interpretation of the meaning):
“And (remember) Loot (Lot), when he said to his people: ‘Do you commit the worst sin such as none preceding you has committed in the ‘Aalameen (mankind and jinn)?
Verily, you practise your lusts on men instead of women. Nay, but you are a people transgressing beyond bounds (by committing great sins)’” [al-A’raaf 7:80-81]
“Verily, We sent against them a violent storm of stones(which destroyed them all), except the family of Loot,…” [Al-Qamar 54:34]
And The Prophet (peace and blessings of Allaah be upon him) said: “… cursed is the one who has intercourse with an animal, cursed is the one who does the action of the people of Loot.” (Ahmad).
In another narration, he said: ‘Whoever you find doing the deed of the people of Loot, kill the one who does it and the one to whom it is done.” (al-Tirmidhi, Abu Dawood, Ibn Maajah).
Ibn al-Qayyim said: Both of them – fornication and homosexuality – involve immorality that goes against the wisdom of Allaah’s creation and commandment. For homosexuality involves innumerable evil and harms, and the one to whom it is done would be better off being killed than having this done to him, because after that he will become so evil and so corrupt that there can be no hope of his being reformed, and all good is lost for him, and he will no longer feel any shame before Allaah or before His creation. The semen of the one who did that to him will act as a poison on his body and soul. The scholars differed as to whether the one to whom it is done will ever enter Paradise. There are two opinions which I heard Shaykh al-Islam (may Allaah have mercy on him) narrate.” (al-Jawaab al-Kaafi).
…Abide by the truth even though your mind deserts you.