Wolfhart Pannenberg is considered one of the most important theologians of the twentieth century. In this dissertation, we analyze how Pannenberg saw the Church in the context of the godsend of the Spirit and as an eschatological sign of the kingdom of God. The process we used for the study was: first to present a summary of Pannenberg s life and work; then discuss the general elements of his theology, the author s explanation for the need of systematic theology in modern secular society as well as including some remarks about the role of ecclesiology. Finally, we focus on the main object of this dissertation – the two topics indicated above which are included at the beginning of the third volume of Systematic Theology. On these two topics, we stress that, per Pannenberg, the Church is directly related to the Holy Spirit, since the Church is only a sign of the forthcoming reign of God because it receives the action of the Spirit as an eschatological godsend. We also discuss that the Church differs from the kingdom of God, because it is only a sign and therefore an anticipation of it instead of being the kingdom of God itself. According to Pannenberg, the Church is the body of Jesus Christ and, thus, it is the representation of the mystery of salvation. We also conclude that Pannenberg s theological thinking has contributed to the Church s dialogue with modern society and it is a piece that still has much to contribute today. For this reason, the study of his ecclesiology is relevant to the implementation of pastoral work that is relevant to the concrete reality of human beings.