He has noted the question you had asked concerning the problem of marriage, and its infrequency among the believers in general. It is indeed a matter of deep regret to him that some of our young believers do not attach due importance to the question of marriage, and seem, as you state, to be under the impression that marital life has been discouraged in the Cause. This is certainly an erroneous conception, and whosoever takes the pain to carefully and intelligently read the words of Bahá'u'lláh, and to ponder over their implications, cannot but be convinced of the truth that in the Bahá'í Faith marriage, and family life, in particular, are both not only commendable, but constitute a social function of highest and indeed vital importance, as through them alone the human race is perpetuated.
The believers should well know that whereas Bahá'u'lláh has not made marriage a binding obligation, He has nevertheless attributed to it such spiritual and social significance as no individual believer, under normal circumstances, can well be justified in disregarding it. In fact, in His Book of Laws (the "Kitáb-i-Aqdas") He emphatically stresses its importance, and defines its essential purpose, namely the procreation of children and their training in the Religion of God, that they may know and adore Him, and mention and praise His Name. (From a letter written on behalf of Shoghi Effendi to an individual believer, dated 17 February 1940; The Compilation of Compilations, vol. I, Preserving Baha’i Marriages)