“The love between husband and wife must not be purely physical”: - “spiritual and heavenly”

The friends of God must so live and conduct themselves, and evince such excellence of character and conduct, as to make others astonished. The love between husband and wife must not be purely physical, nay, rather, it must be spiritual and heavenly. These two souls should be considered as one soul. How difficult it would be to divide a single soul! Nay, great would be the difficulty! 

- 'Abdu'l-Bahá’  (From a Tablet, The Compilation of Compilations, vol. I, Preserving Baha’i Marriages)