The gradual but steady decline of religion across all human societies of the world in an increasingly secular world cannot be denied. Religious beliefs and dogmas are among the most radical and changeless world-views which form the building-blocks of major aspects human morality, culture and traditions over time. However, due to the fact that human culture is very dynamic and open to new forms and adaptations deriving from cross-cultural interactions, the religious foundations of morality and culture necessarily come under pressure and are undercut through the unrelenting progress and widening spectrum of human civilization, and the subsequent larger horizon that the forces of globalization afford to people to encounter new things in modern times. Using mainly secondary sources of information gathering and analysis of works written on this and other related topics, this work enquires into the challenges inherent in trying to maintain the orthodox teachings of Judeo-Christianity among the younger generations of Christians in Nigeria and elsewhere, against a background of the permissiveness occasioned by the moral and cultural leanings of the modern secular world. This paper surmises from its findings that the fundamentalism inherent in religious orthodoxy, which gives no room for doctrinal compromise and adjustment, is one of the major causes of the declining interest of the youth in church activities in Nigeria, and in the general decline of Christianity and faith-based culture and traditions in the modern secular world. Thus, the continued tension and stress generated by the imperative of change through the preferences of the secular culture constantly facing off with the unchanging nature of God and religious beliefs would likely continue to work against the progress of religion in modern times, and aid the further decline of Christianity in the Nigerian society and presumably, in other parts of the world.