What makes extramarital sex a sin?
1. Pre-fall creation covenant.
It’s part of our nature- it’s deeply rooted in our being and essence that we desire “love making” to be in that married state. This is evidenced by the fact that God’s initial creation of Adam followed shortly by the help-mate Eve so that man might leave father and mother and cleave to his wife is stated before the Fall ever occured.
IF marriage had been instituted as a result of the Fall, then a good argument could be made that marriage isn’t foundational and core to our essence as humans who love.
Our very being goes back to that desire to cleave to one another, man and woman, just as we would have had there never been Sin brought into the world.
The contrary is also helpful to look at. What makes homosexual sex a sin? It, among other things of course, is inconsistent with the creation covenant. Homosexuality does not come around until after the Fall. To be out of sync with the creation ordinance is to be in sin.
Anytime somone is engaged in extramarital sex they are acting in disregard for the original creation account, they are inconsistent with the way Man was created… the way man is in essence.
2. Sacrament of the Church
Marriage is perhaps the most important Sacrament of the church outside of Holy Communion (arguably) – it is a foundational institution of the Church.
This is crucial because it is the Sacraments that literally imbue meaning/holiness to our mundane actions. IF Communion isn’t a Sacrament of God…. then we’re just eating bread and drinking wine… IF Baptism isn’t a Sacrament of God…. then we’re just getting wet.
IF these things are not Sacraments…. it’s nothing more than “sound and fury signifying nothing” as Shakespeare would say.
Hence, IF sex is taken outside of marriage (the Sacrament) it’s just rubbing bodies together… it’s no different than what two giraffs do in the African deserts.
So why is rubbing bodies together sinful? Because we can’t have it both ways. We either 1. Want to say it’s meaningful, and therefore can only find its meaning in the Sacrament, by definition…. OR 2. We want to say it’s meaningless… (oh wait, we dont want to say that….) that’s the point…. no Christian wants to say it’s meaningless. If you found a Christian that does…. they have to own that (an impossibility because of the creation covenant), … or they can live their life having admittedly and openly “meaningless” sex.
To put this point another way: the only way to get sinless extramarital sex is to take God and the Church out of the conversation completely.
As a Sacrament the act is defined by and sanctioned (owned by if you will) the Church/Christ. Hence, sex is defined by Christ…. in a sense Christ owns the very institution and instantiation of it.
3. Analogous to the Marriage of Christ to the Church.
Since marriage is the type of Christ’s connection to the Church, there is some mystical and meaningful reality to sex that is outside the scope of this author.
In this reality perhaps we find a real world experiential type of what joy and pleasure awaits us in heaven. I’m speculating here.
All this to say that there’s something meaningful in oneness, communion, marriage, creation/re-creation/procreation, and Christ’s connection to the Church…. to us.
Sex being part and integral to marriage and the marriage covenant relies on that mystical reality to maintain its purity. Removed from this, and its confounded in perversity.
4. If sex is performed outside of the marriage covenant, it ceases to be beautiful, but only a rebellion, regardless of how good it feels, or how “sincere” the participants are.
Sex is described by many heathens as “beautiful” “wonderful,” “majestic,” and even “religious.” Homosexuals describe their sexual acts in this way. Those involved in incestual relationships make the same claims. Those engaging in sexuall acts with numerous partners describe the same exstatic experiences and descriptions. What difference then does the Christian respond with?
The answer is epistemological. We either have a system of ethics prescribed for us in the Bible, by God, unalterable… or we don’t.
If we don’t, then all is permissable… and indeed no one act would be any more or any less beautiful than any other because we’d be left in a world of relative morals, amidst a random chaotic world. (This is the first alternative) There is only one other.
If we DO have an unalterable, prescribed ethical system laid down in the Bible by God then we must go there for defining our ethics. Those ethics in regards to sex are pretty clear. Do it with your wife and with no one else. Don’t do it with your brother or sister or with animals or with someone of the same sex. That’s about it. God is pretty clear.
Hence, IF we don’t want to simply follow the Bible… see the first three reasons for help…. then we can throw out the Bible and be left in a relativistic, random chaos of actions where everything is OK, and nothing sacred (or beautiful).
In other words, there is but one choice to accomodate our presuppositions about life and living in accordance with the truth we know through faith.