The Church is also called to build up God’s Kingdom which is a reality present in time, but whose full realization will arrive only with the completion or fulfillment of history. This kingdom according to the Holy Father is the concern of everyone:

“Individuals, society and the world working for the kingdom means acknowledging and promoting God’s activity which is present in human history and transforms it. Building the kingdom means working for liberation from evil in all its forms. In a word, the kingdom of God is the manifestation and the realization of God’s plan of salvation in all its fullness”. (Decl. Dom. Jesus 13)

 Many Christians often get confused when we talk about the mystery of the Church. This problem is worsened in our country by religious pluralism and the threat of Pentecostalism which has led to the proliferation of Churches. The Document, Dominus Iesus has once more reaffirmed the teaching of the magisterium that the Church subsists in the Catholic Church:

“This is the single Church of Christ…which our Saviour, after his resurrection, entrusted to Peter’s pastoral care (Jn. 21:7), commissioning him and the other Apostles to extend and rule her (cf. Mt. 28:18ff), erected for all ages as ‘the Pillar and Mainstay of truth’ (1 Tim. 3; 15). This Church, constituted and organized as a society in the present world, subsists in the Catholic Church, governed by the successor of Peter and by the Bishops in communion with him”.

It is part of the mission of the Church and of her members to bring all the scattered children of God into one Communion of faith so that just as there is one Christ, so there will exist a single Catholic and Apostolic Church. This idea of unity is expressed in many biblical images of the Church, namely: The Mystical Body, the People of God, the temple of the Holy Spirit, the Flock and Sheepfold, the House in which God dwells with us, the Bride of Christ, Our Mother, the Holy City and the first fruit of the kingdom to come among others. Our work of evangelization must aim at building a communion of all believers and not to create a federation of Churches:

The Christian faithful are therefore not permitted to imagine that the Church of Christ is nothing more than a collection – divided, yet in some way one – of Churches and ecclesial communities; nor are they free to hold that today the Church of Christ nowhere really exists, and must be considered only as a goal which all Churches and ecclesial communities must strive to reach. (Declaration Dominus Jesus No. 17)