Martinus: Livets Bog, vol. 4, sect. 1206

1206. But in addition to the marriages mentioned here that result in divorces and new marriages, there are also marriages that last an entire terrestrial lifetime, not because the couple do not feel any of the same longing for freedom or the same attraction towards other sexual partners – on the contrary, this longing is present in the great majority – but because, for moral or religious reasons alone or out of fear of going against the inherited, authorised moral traditions, they are tied and bound by these traditions, just as their love for any children in the marriage can be so strong that, for this reason alone, they combat their inner nature that is undermining marriage, and keep their married life within the traditional, authorised framework.
But marriages in which the traditional, marital customs are not observed solely on the basis of the couple's amorous love for one another or most profound sexual attraction, but must be shored up by traditional, moral views and fear of people's opinion, criticism and scandal, or marriages that are maintained absolutely only by the couples' conscience or feeling of duty and fidelity to a promise once given and by reluctance to cause or fear of causing the other party sorrow, are neither one-hundred-per-cent happy marriages nor one-hundred-per-cent in contact with the sixth commandment or God's words to "Adam" and "Eve" about marriage. The partners in such a marriage are not the perfect, inspiring source of life for one another that, according to the law of marriage, they ought to be. Since the beings in no small degree feel attracted towards other beings or sexual partners, even though they keep it hidden or under control, they still commit "adultery". Did not Christ say: "That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart"?