The fact that the contemporary society is witnessing much disturbing increase in marital instability characterized with violence to physical and mental separation is no longer in doubt. Marriage as a divine institution was founded by God on the purpose and principle of fellowship, companionship, procreation and education and training of children for societal progress and well being. Marriage has legal, traditional, cultural and religious affinity and as such is socially viewed as being sacred. However, some intellectuals and Christian theologians in their debate have viewed certain factors as being responsible for this increase in marital instability, among which are, cultural, social, physiological, economic, religious, moral and biological. This paper examined both the legal and theological perspectives of marriage union between a man and a woman and the challenges of marital separation (physically or mentally) on child’s development and the society at large. The study recommends in a strong terms a reinvigoration of efforts to enforcement of child’s right of victims of marital separation to education and care and as well, promoted responsible training of the younger ones on family and marriage values both in the church and in Nigerian schools towards sustainable marital values and stability.