This is a letter by Srila Prabhupada to his disciple Gaura Hari explaining how devotee marriage should be considered a contract of spiritual wedlock.
Please accept my blessings. I beg to thank you for your nice letter dated 26 Damodara 484 Caitanya Era. It is my great pleasure that so many fine young boys have joined this Krsna Consciousness Movement and they are finding that their lives have been saved by this simple process. I have many times expressed my sympathy with the frustrated and unhappy younger generation of your country and it is our duty to teach them this formula for peace and happiness by chanting the Mahamantra. This is the business of a devotee, he himself finds the secret that by simply loving Krsna one automatically acquires love for all other beings and he takes it as the prime duty of life to spread this sublime knowledge to everyone he meets.
I am very glad that you have decided to become a Grihastha member of our Society. That is the way of civilized and upright human life. After practicing brahmacarya and training under the guidance of a Spiritual Master the Vedic system is prescribing the asrama of Grihastha for those who are still desiring to enter into married family life. The so-called institution of free love marriage is ruining the human society and it is our duty therefore to reestablish the correct procedure of human life in the matter of encouraging our disciples who wish to marry to enter into a contract of spiritual wedlock. Such contract is made on the basis of compatible service of the Lord because such mutual cooperation in serving the advancement of Krsna Consciousness minimizes the illusion of material compatibility and incompatibility. We are seeing practically that our householder couples are setting an example for all persons that the perfection of happy family life is not based on sense-gratification, but on sincere service to the Lord.
I have already replied to Sriman Locandas the circumstance concerning the girl, Lisa, whom you mentioned. Anyway, if you make either this arrangement or some other, I shall be pleased to offer my blessings upon you both in your marriage. Simply be anxious to keep your life, married or otherwise, always on the platform of pure devotional service to Krsna and be happy chanting Hare Krsna.
Hope this will meet you in good health.
Your ever well-wisher,
A.C. Bhaktivedanta Swami