Where do the scriptures speak of a "Church Universal" on Earth?

The Apostles' Creed contains the phrase "I/We believe in the Holy catholic Church". We are told that "Catholic" meant the "universal Church" (though I'm convinced that it was referring to the specific group of Roman clergy, faithful to the Imperator). I'm not familiar where the "universal Church" is discussed in the scriptures. Obviously "Church", the English word, was coined after the writing of the scriptures (since it is English) and originally referred to a building. So can someone break down for me what a "Universal Church" might be, specifically? Whence did the name and concept of a "Universal Church" arise? Does it refer to the property, government or the people? Where is it located? What is the scriptural basis? Since "Catholic Church" is not in the scriptures, why do Protestant assemblies assent to an unscriptural creed?