Here is how the Heidelberg Catechism captures this truth:
If you would like to read the whole of the HC, which I strongly recommend that you do, then you can find it here. And by the way this online version has Bible references also. Not surprisingly there are five references to John 10 for this question.
Q 54. What do you believe concerning the “holy catholic Church?”A. That out of the whole human race, from the beginning to the end of the world, the Son of God, by His Spirit and Word, gathers, defends, and preserves for Himself unto everlasting life a chosen communion in the unity of the true faith; and that I am and forever shall remain a living member of this communion.