The theme of Christian witness and all the sacramentality involved in it is the main focus of this work. Initially, the theme of Christian witness as a martyrdom is highlighted in a brief historical way, in addition to the focus on witness in the profane and religious perspectives, as well as in recent Ecumenical Councils and in the post-conciliar magisterium of the last popes. It is verified that the Christian witness has considerable weight for the Church s credibility factor, being even a necessary first condition for the credibility of the faith, since many people no longer believe in the institution, but they do not deny the reality of an evident Christian witness. Based on Salvador Pié-Ninot s Ecclesiology, we seek to highlight the issue of the sacramentality of the Church as a new sociocultural issue. The notion of the Church-sacrament is explored in its indoor sign, as a community; and in its outdoor sign that evidences the Church as a society and all the aspects derived from it. For Pié-Ninot, witness is seen as a key element of credibility in the Church and becomes known as via testimonii, as it is the most emphatic, notorious and coherent way of evangelization. Therefore, the two previous notions are united, seeking to achieve a mixture of Christian witness as a matter of sacramentality of the Church, in which the heresies that the world represents today, neognosticism and neopelagianism, are opposed through the orthodoxy of Pope Francis. This work is concluded, highlighting the Christian witness as a sacramental of the Church, which refers to the primordial Sacrament, which is the Church, in an ecclesial and theological perspective.