The present dissertation focus upon the influence of post-modern individualism on contemporary western christianism. We have shown, thru thinkers like, for example, Gilles Lipovetsky and Danièle Hervieu-Léger, that post-modern society, fragmented, multifaceted, globalizer and supporter of a selfcentered emphasis on individuals has also generated on christian religious communities, the same individualism to be found outside the christian environment, in a secularizedsociety. As a possible response to such growing individualism in religious christian communities we have tried to revive the central ideas of catholic philosopher Emmanuel Mounier, mainly thru his work entitled The personalism. His personalistic philosophy stresses the singularity of the person and its freedom - not to be understood as part of an anonymous and faceless mass - the indispensability of of a communitary life to a really authentic living and thesymbol of the trinity as reference to the human community. Theologian Karl Barth will reinforce some of the ideas fostered by the personalim of Mounier, emphasizing, however the central aspects that touch upon the christian faith. Barth, thru his theology, will present what he calls the necessary co-humanity, that is, the exchange and fruitful experience among human beings by way of a solidary and communitary life, and will present the figure of Jesus Christ as a reference to be followed whether towards human beings as well as towards God.