Preservation of the Church

The following is from Martin Luther's Bondage of the Will.

In the first place, we do not say that this error was overlooked of God in His Church, or in anyone of His Saints. For the Church is ruled by the Spirit of God, and the Saints are led by the Spirit of God. (Rom. viii. 14.) And Christ is with His Church even unto the end of the world. (Matt. xxviii. 20.) And the Church is the pillar and ground of the truth. (1 Tim. iii. 15.) These things, I say, we know; for the Creed which we all hold runs thus, "I believe in the holy Catholic Church;" so that, it is impossible that she can err even in the least article. And even if we should grant, that some of the Elect are held in error through the whole of their life; yet they must, of necessity, return into the way of truth before their death; for Christ says, (John x. 28,) "No one shall pluck them out of My hand."...

But, look at the people of Israel: where, during so many kings and so long a time, not one king is mentioned who never was in error. And under Elijah the Prophet, all the people and every thing that was public among them, had so gone away int idolatry, that he thought that he himself was the only one left: whereas, while the kings, the princes, the prophets, and whatever could be called the people or the Church of God was going to destruction, God was reserving to Himself "seven thousand." (Rom. xi. 4.) But who could see these or know them to be the people of God? And who, even now, dares to deny that God, under all these great men, (for you make mention of none but men in some high office, or of some great name,) was reserving to Himself a Church among the commonalty, and suffering all those to perish after the example of the kingdom of Israel? For it is peculiar to God, to restrain the elect of Israel, and to slay their fat ones: but, to preserve the refuse and remnant of Israel, (Ps. lxxviii. 31.; Isaiah i. 9., x. 20-22., xi. 11-16.)

What happened under Christ Himself, when all the Apostles were offended at Him, when He was denied and condemned by all the people, and there were only a Joseph, a Nicodemus, and a thief upon the cross preserved? Were they then said to be the people of God? There was, indeed, a people of God remaining, but it was not called the people of God; and that which was so called, was not the people of God. And who knows who are the people of God, when throughout the whole world, from its origin, the state of the church was always such, that those were called the people and saints of God who were not so while others among them, who were as a refuse, and were not called the people and saints of God, were the People and Saints of God? as is manifest in the histories of Cain and Abel, of Ishmael and Isaac, of Esau and Jacob. [Sect. 32]