So how do you find a partner? And if you cannot desire having sex with them before you're married how do you ensure that you marry someone that you desire sex with? Seems like if you only marry someone that all through the relationship you haven't desired, you're asking for a lot to suddenly find them attractive in that way now that you've married.
You're thinking with a secular mindset, and not a Holy/Godly mindset.
#1: Sex should not be based upon lust, but rather upon love.
#2: Attraction to a person should not be based upon lust, but rather upon love.
See, all things that come from God are based upon Love.
How do you find a partner?
You go out and you make friends. Let's say you know 5-10 ladies who are your friends. Perhaps one day, one such friend who is single, you mind find yourself really enjoying their company, you enjoy talking to them, you enjoy being with them more and more and they feel mutually the same.
Then, the idea of getting together comes up, and it is agreed upon that the two should start dating (no sex!) and after several months, or a year, or two whatever, marriage is agreed upon, and bam. Married.
Marriages built upon sex and lust just don't work for the most part, because there will be a day where the personality clashes will become too great, or one or the other partner will find someone that they desire
more than their current partner, and then you're looking at infidelity, adultery, and/or a divorce, especially as they age. A couple that falls in lust for one another when they are 20 might end up with problems when they are 40 when both have gained some weight, and are older and are no longer attractive to each other.
HOWEVER, the Marriage that is founded upon genuine love, and an attraction of personalities should continue to blossom even when they don't look as physically good as they once did.
And to be truthfully honest... does the woman really have to look like a supermodel for you to be able to want to have sex with her? Obviously, many people couldn't go for someone who, say, weighs 500lbs, but for most of your average women who are not incredibly obese or anything, are you really trying to say there are women that you just could not have sex with if she were your wife? Is looks all there is to a woman? Has our society fallen that far, where there are Christians who believe that physical beauty is the defining factor in a woman?
Are we not taught the higher meanings of Love?
Sex should happen when the married couple wants to express love for each other, not lust. Sex should happen when the two want to come together and experience the gift that God gave them, rather than when their hormones are jumping. Not saying that hormones don't play a part in even the most Godly marriages, but that shouldn't be the primary reason.