In another letter Paul makes a distinction between works of the flesh which are all within our power and fruits which we cannot produce by trying. We can easily be immoral, worship an idol, engage in witchcraft, make enemies, start a quarrel, be envious, get drunk, have an orgy. But love, joy, peace, patience, kindness, generosity, faithfulness, gentleness, and self-control are fruit and they can only be grown by the Spirit. And these are precisely the fuits that we need for God's kind of love in our marriage. Obviously nobody is totally devoid of all these qualities.
Some people are by nature kinder, more optimistic, and self-controlled in some areas than others.
Paul's point is that if we find a lack of fruit in our lives we cannot conjure it up by the flesh. For genuine long term love in marriage we need the inspiration of the Holy Spirit. And seeking inspiration is a matter of setting our mind on it, or as the Greeks called it wooing the Muse. The apostle's use of the word mind is important. Our minds are constantly active.