It seems to me in a good marriage there is something more than can be explained in biology. Regardless of whether a person can explain what it is do atheist believe love is a real thing, you know.. "true love."
The experience one labels love involves a complex system of proccesses in the brain, involving many different areas, from the primary cortices of the senses, the autonomic centres governing subconcious actions and reactions like heart rate and pupil diameter, the emotional learning and memory areas of the lymbic system, and the frontal cortex of decision making. This is to but name a few, all of it is interconnected with association pathways, and has been tweeked, and changed over time in response to your life experiences as a result of the process known as neuro-placticity.
Of course theres no inherent measurment for love, when does it change between 'really like' and 'love' is a very subjective thing, and i guess it has to be. I guess its the upper limit of emotion experienced by the individual in question, Which would explain teenage crushes, which at the time feel like love.
Its existance is unquestionable though, even if you ignore the fact pretty much everyone experiences it (whether or not they decide to label it love), it demonstrates massive evolutionary and survival benefits, suggesting its evolutionary roots and obvious natural progression from instinctual behaviour to the more complex nature of it today fitting in with the equally complex nature of the human mind.
As a non-theist i completely recognise the existance of love as a feeling for an individual. God though i dont recognise as clearly existing outside the minds of individuals. Im not sure why atheist are assumed to be present is society to reject everything
Biological explanation should not be-little or change what love is. Remember you are that biology being explained, so of course it feels damn real to you.
So love is believed to be real by most atheist, but also a part of nature. Would love be described in psycholgical terms in the same category as lust or is it something completely diffrent. A Frued said alot about lust, did he say anything about love.
The difference between love and lust is that love is a larger umbrella term for emotional activity in the brain. Love not only being a massive mix of activity as stated above, is also almost sequntial in nature from the moment you lay eyes on the person, through the various avenues of interactions from language to touch, to the rewiring of the brain neurons in response to knowing and being with the person. (neuroplacticity again). Explains the pain when you loose someone, and the latent feeling of them still being around. (because technically as far as aspects of your brain are concerned they are, untill it can rewire yet again). Very phantom-limb in nature.