A Voice from the Past - Zwingli

This I met thus: “Let not this exhortation move you, most excellent citizens, as if you had ever abandoned the Church of Christ. For I am persuaded of you that you hold in fresh remembrance what is said in the narrative of Matthew, that the foundation of the Church is that rock which gave his name to Peter the faithful confessor. No one lays other foundation than this, nor can do so. Nay, in every nation and place, every one who confesses the Lord Jesus with his tongue and believes in his heart that God raised him from the dead
shall be saved, whether he be among the Indians or the Scythians, and it is fixed beyond controversy that outside of that Church none is saved, within which we all believe ourselves to be the more firmly as we glory the more certainly in the hope of the glory of the sons of God.”
Huldrich Zwingli, 1482-1531, Letter to Erasmus Fabricius (Selected Works of Huldrich Zwingli, Samuel Macauley Jackson University of Pennsylvania, 1901, p.26)

How should we understand what the Christian church is? What practical impact does this have?