"Homosexuality is a genetic disorder"
I don't think disorder is the right word for it.
"At contrary, they tends to prove that homosexuality is basically normal."
I don't think normal is the right word for it either.
Homosexuality is a natural and harmless anomaly that affects a small percentage of sexually reproducing species.
Disorders are deleterious disruptions of the normal functioning of the mind or body. Being attracted to the same sex is not a deleterious disruption of the functioning of the mind or body.
However, homosexuals have bodies that are "designed" for heterosexual intercourse, so the fact that they are sexually attracted to the same sex does not fit with their "design" and so is not normal.
So homosexuality is basically a harmless anomaly affecting a small percentage of sexually reproducing species. Given that it is harmless, there is no point in treating it or trying to outlaw it or trying to restrict the desires or sexual privileges normally afforded to heterosexuals.
Discriminating against homosexuals is as stupid as discriminating against left-handed people.
The bible is a backward book written centuries before the dark ages, when ignorance, prejudice and superstitions reigned supreme. It is foolish to look to a book that condones/orders genocide, slavery, misogyny, etc, as an infallible moral guide of right and wrong.