Do we really need to have s*x with our spouses in order to keep our relationship alive?
I suppose not, no - but it will necessarily be to the mental/psychological detriment of one (or both) of the partners who does still have a sex drive, or instincts influencing their thoughts and desires.
Can couples stay in love forever without having s*x?
Probably, yes.
If not, then why is copulation so important in a relationship?
Because there are biological drives that can't be helped. There they are, and they are requesting satisfaction, regardless how much you "wish them away." If someone loves another, and understands these types of drivers, then why wouldn't they want to accommodate if they are able? It would be much like a female having an extremely high drive to become a mother, and desiring this without being able to control it. If the male partner she is with is completely against the idea of having children, do you, as a discerning member of humanity, chastise her desires to mother a child if she decides that the feelings she is having are too important and that she can't stay in the relationship where she is unable to satisfy these feelings she has? If your answer is "yes" - that you would look down on her or judge her harshly for leaving a relationship where her partner is unwilling to help her satisfy this urge that her body/mind is telling her is of the utmost importance, then so be it. But if you wouldn't, then I would implore you to look at the drives behind sex, compare them to the drives for wanting children, and answer the question "what is so different about these drives?" They are both items related to the body/mind's innate drive toward reproduction, and they are both things that can't be helped by the person experiencing them.
What if we (humans) were born without reproductive organs and without any s*x drive ... and instead reproduced asexually like the amoebas, by splitting into two.
In the end, this doesn't describe the sexuality of human beings. Let's stick with reality here. It doesn't matter what we would do if we were asexual. We aren't. If we were, then things likely would be very different, yes. But facts are what they are, and that is the reality that must be dealt with. Not "if you were asexual, you wouldn't even want to touch my body - so don't touch my body." A statement like that one is to be heard out of a completely irrational mouth.
In my opinion, true love (between spouses) should be without any kind of sexual intimacy.
Should be? Is there an "ought" here that makes any sense? Again, if someone loves you, and can help you satisfy various urges (that can culminate in being or remaining quite uncomfortable for some people I might add), why wouldn't they want to do so? If people's intrinsic desires/wants/urges do not matter, then why does anyone feel the need to apologize to their spouse if they find out they are unable to have children? For that matter, why worry about providing sustenance in the form of food, shelter or clean water for your spouse? Shouldn't they just provide for themselves? Why do you care about the intrinsic feelings that drive them to what they want or need?
Love is a beautiful thing while lust is nothing but hunger of the body.
It is sad to me that you think this way. Sex is one of the few grandly enjoyable experiences of this world - or, I should say, it can be. If it is not, then you are probably with the wrong person, or
you are the wrong person - such that things are uncomfortable, or you are made to feel uncomfortable, or you make the other person feel uncomfortable. It doesn't have to be that way, and can be mutually enjoyable to a very high degree.
When such a hunger is satiated we usually move on and look for another partner
What is this? "When the hunger is satiated" then a person moves on? How strange. Usually I have heard tell that it is when certain wants aren't being met that there is a person seen "moving on." If things are copasetic or better, what reason has anyone to "move on?"
That is not love, if you ask me.
You can tell me all about it when I actually
do ask you.