When He clarified that marriage is a life-long commitment and pointed to scripture and pointed out it emphasized that God had created people as different genders to that purpose. He also points out that there will be those incapable of marriage based on how they were created, or via the choice they made. Note, Paul in his letters emphasizes this teaching and explains that homosexual acts lead to condemnation (note, he didn’t say homosexuality beyond one’s control, but the homosexual acts done by choice).
Matthew, 19
4 He answered, 'Have you not read that the Creator from the beginning made them male and female 5 and that he said: This is why a man leaves his father and mother and becomes attached to his wife, and the two become one flesh?
6 They are no longer two, therefore, but one flesh. So then, what God has united, human beings must not divide.’
7 They said to him, ‘Then why did Moses command that a writ of dismissal should be given in cases of divorce?’
8 He said to them, ‘It was because you were so hard-hearted, that Moses allowed you to divorce your wives, but it was not like this from the beginning. 9 Now I say this to you: anyone who divorces his wife – I am not speaking of an illicit marriage – and marries another, is guilty of adultery.’ 10 The disciples said to him, ‘If that is how things are between husband and wife, it is advisable not to marry.’
11 But he replied, 'It is not everyone who can accept what I have said, but only those to whom it is granted. 12 There are eunuchs born so from their mother’s womb, there are eunuchs made so by human agency and there are eunuchs who have made themselves so for the sake of the kingdom of Heaven. Let anyone accept this who can.
