This is a subject that is near and dear to my heart, and as luck would have it I just got this article yesterday which will hopefully aid in a discussion.
What Is Physical Happiness?
Abdu’l-Baha wrote: The physical happiness is limited; its utmost duration is one day, one month, one year.
This fleeting feeling of physical happiness comes from four neurochemicals: dopamine, endorphin, oxytocin, and serotonin.
“Dopamine produces the joy of finding things that meet your needs—the ‘Eureka! I got it!’ feeling. Endorphin produces oblivion that masks pain—often called euphoria. Oxytocin produces the feeling of being safe with others—now called bonding. Serotonin produces the feeling of being respected by others—pride,” explained Dr. Loretta Graziano Breunig in her book, “Habits of a Happy Brain.”
For example, we feel a surge of dopamine when we taste a really good meal for the first time, endorphins after a new strenuous and satisfying workout, oxytocin from hugging a loved one, and serotonin after a big promotion.
But, the happy feeling that each of these neurochemicals gives us is temporary.
What Is Spiritual Happiness?
Abdu’l-Baha
said: The physical happiness of material conditions was allotted to the animal. …This is the honor of the animal kingdom.
But the honor of the human kingdom is the attainment of spiritual happiness in the human world, the acquisition of the knowledge and love of God. The honor allotted to man is the acquisition of the supreme virtues of the human world. This is his real happiness and felicity.
Our true happiness is based on our spiritual behavior. When we know and love God and acquire all the virtues that we will need in the next world, we make it possible for our souls to “find happiness both in this world and the next.” This eternal spiritual happiness appears when our hearts are illuminated with the light of the love of God.
https://bahaiteachings.org/What’s the Difference Between Physical and Spiritual Happiness?
The above excerpt from an article applies to anything in this physical world that makes us happy, but since the topic of sex has been a hot topic on this forum lately I would like to share what I believe about it. I have argued that sex act is a physical act that is engaged in for physical pleasure, while some others have argued it is spiritual. I do not believe the sex act is spiritual, not according to my understanding of spiritual, as noted above.
The effect of the sex act upon the body is an established scientific fact.
Does sex release happy chemicals?
Sexual intimacy can also help reduce feelings of anxiety and depression as it triggers the release of three mood-boosting chemicals — dopamine, endorphins and oxytocin. Feb 22, 2021
6 health benefits of sex
Sure, people are happy during and for a short time after sex, but people are also happy from drinking alcohol or taking drugs that induce happiness. Are those spiritual experiences? Granted, there can be a component of love with sexual expression, so that is a difference. However, sex is still a physical act that is unrelated to knowing and loving God or acquiring spiritual virtues, so I cannot see how it could possibly lead to spiritual happiness as defined above, although it does not necessarily thwart spiritual happiness.