Prior articles have addressed the Torah’s perspective on SSM and the basic reason it is outlawed.
This article is about the negative effects on the individual LGBT practicing SSM – physical, mental, and spiritual.
SSM & Nature
LGBT have a desire for SSM.
On an intellectual level however, there is no rationale for SSM:
Males and females are physically compatible. Male-to-male is not.
The AoM creates life. Hence the desire for it makes sense, because it brings to creation. That is how humanity will perpetuate and the world continue to exist. SSM is purely for pleasure. There is no beneficial outcome the results from fulfilling this pleasure.
Hence the drive for AoM is only active during a person's life when he and she can get married and give birth. Not younger than that (under puberty) or older than that (past menstruation).
Animals also conduct AoM. This is how they perpetuate. They don't do SSM.
That's why the Torah only uses the term "תועבה" ("To'eva", literally translated as "abomination") in connection with forbidding SSM, and not with any other forbidden relationships associated with women: This term means "תועה אתה בה" – "You are mistaken with this desire". The lust for SSM takes the person in the opposite direction to where the sexual drive is meant to lead him/her.
Nature (how G-d created it) operates in the fashion of compatible mating and perpetuity. SSM goes against that.
SSM causing harm to the individual
Engaging in SSM increases the risk of the following ailments:
Cancer (prostate, testicular, colon, breast (Lesbians))
Eating disorder (bulimia , anorexia nervosa)
Sexually Transmitted Diseases (HIV/AIDS, syphilis, gonorrhea, chlamydia, pubic lice, anal papilloma, hepatitis virus, human papillomavirus)
Mental health disorders are also more common by LGBT who engage in SSM:
Post-traumatic stress disorder
These in turn cause higher consumption of tobacco, alcohol, and drugs, and higher rates of suicide.
Harm to others?
What harm does SSM cause anyone else?
Yes, it is not pro-creative, and that has a social impact (discussed in the next article).
But it is not a direct act against G-d (like the first two Noahide Laws).
It doesn't seem to hurt or otherwise disturb anyone and anything (like the last five Noahide Laws).
Why then is SSM forbidden, and so fundamentally?
The power of creation
The AoM brings into existence the most powerful achievement humans can ever have.
More than a noble prize, international fame, or even saving lives. These achievements shape what is already in existence.
The AoM creates existence. It creates life from nothing:
Every emission of semen contains many souls.
If conceived by the female through an AoM, one of these souls will go through a physical birth process, as we know it.
All the other souls in such an act will also be born (through the female) but in other forms (see notes further down).
So every AoM creates life when done normally.
However, if it is done otherwise (SSM, Sodomy, or Maturbation) – it is wasting that life, effectively murdering all those souls.
There are different levels of taking another's life away:
Murdering of another person. That's the most apparent level
Aborting of a fetus in his mother's womb
Wasting semen (via non-procreative sexual activity). That's the least apparent level.
In terms of punishment, the more apparent the murder, the more severe is the punishment.
But in terms of the impact, it is the other way around, as one would (G-d forbid) kill his own children (in the case of abortion), or many of them (in the case of wasting semen).
NOTES & REFERENCES
SSM is nonsensical. Sefer Hachinuch Mitzva 209.
Animals do not do SSM. Only (some) humans have a desire for SSM. That's because only humans have the responsibility to fix their propensities, and hence they are the only creature born with faults (by default, so they may fix them).
You are mistaken with this (SSM) desire (תועבה). Talmud Nedarim 51b.
Therefore a man shall leave his father and mother, and cleave to his wife and become one flesh. Genesis 2:24. This is the verse from which we learn that SSM is forbidden: "Cleaving" and "one flesh" in an AoM is only applicable with a man and women, to exclude SSM and human-to-animal: Talmud Sanhedrin 58b.
AoM creates life (when done normally), even if no physical conception takes place. There are different opinions as to the form of such life:
Souls and Angels – Zohar I 12b
Souls that would eventually come into the body of converts – Shela (של״ה) Shaar of the letters, the holiness of the AoM, 402.
Physical children (to the parents involved in the AoM) but born in the Next World – Chida in Midbar Kedemot, 7.
Life to the higher worlds – Ari Zal, Shaar Taamei Hamitzvot, Bereshit. Ben Yehoyada on Talmud Ketubot 62b.
Severity of punishment is in accordance with how apparent the murder is:
Murdering another person intentionally is a capital punishment (Exodus 21:20, Talmud Sanhedrin 52b)
Abortion – there are different opinions: All the way from murder (Igrot Moshe Choshen Mishpat II 69, but no capital punishment) to a Rabbinical prohibition (Responsa of Tzitz Eliezer 8:36).
Non-procreative emission – Excommunication ("נידוי". Rambam Laws of forbidden relations 21:18)
SSM is the least apparent level of murder. There is even a lesser apparent level of murder than non-procreative sexual activity: Refraining from having children (when it is possible), being (only) akin to murder – Talmud Yevamot 63b.
SSM is worse than murder, killing his own children and many of them. Zohar Genesis 219b (with reference to masturbation, but the same applies to SSM (wasting sperm)). Similarly, the Code of Jewish Law (Even Ha'ezer 23:1) refers to this act as the worst of all sins!