By Rafi Eis, First Things - Marriage is therefore a covenant, which emphasizes how the new unit grows together, not what each individual gets out of it. Spouses may have different sexual expectations, and sometimes circumstances interfere with intimacy, but the covenant of marriage requires loyalty and commitment regardless. Pornography destroys that covenantal commitment and feeds existing dissatisfaction with fantasies about what could or should have been. Ultimately, it ruins marriage. Purity of mind, in contrast, increases dedication and builds marriage.