The Bondage of the Will – Martin Luther, The Sovereignty of God

“This, therefore, is also essentially necessary and wholesome for Christians to know: That God foreknows nothing by contingency, but that He foresees, purposes, and does all things according to His immutable, eternal, and infallible will.”

“… it follows unalterably, that all things which we do, although they may appear to us to be done mutably and contingently, and even may be done thus contingently by us, are yet, in reality, done necessarily and immutably, with respect to the will of God. For the will of God is effective and cannot be hindered; because the very power of God is natural to Him, and His wisdom is such that He cannot be deceived. And as His will cannot be hindered, the work itself cannot be hindered from being done in the place, at the time, in the measure, and by whom He foresees and wills. If the will of God were such, that, when the work was done, the work remained but the will ceased, (as is the case with the will of men, which, when the house is built which they wished to build, ceases to will, as though it ended by death) then, indeed, it might be said, that things are done by contingency and mutability. But here, the case is the contrary; the work ceases, and the will remains. So far is it from possibility, that the doing of the work or its remaining, can be said to be from contingency or mutability. But, (that we may not be deceived in terms) being done by contingency, does not, in the Latin language, signify that the work itself which is done is contingent, but that it is done according to a contingent and mutable will—such a will as is not to be found in God! Moreover, a work cannot be called contingent, unless it be done by us unawares, by contingency, and, as it were, by chance; that is, by our will or hand catching at it, as presented by chance, we thinking nothing of it, nor willing any thing about it before.”

“And how can you be certain and secure, unless you are persuaded that He knows and wills certainly, infallibly, immutably, and necessarily, and will perform what He promises? Nor ought we to be certain only that God wills necessarily and immutably, and will perform, but also to glory in the same; as Paul, (Rom. iii. 4,) “Let God be true, but every man a liar.” And again, “For the word of God is not without effect.” (Rom. ix. 6.) And in another place, “The foundation of God standeth sure, having this seal, the Lord knoweth them that are His.” (2 Tim. ii. 19.) And, “Which God, that cannot lie, promised before the world began.” (Titus i. 2.) And, “He that cometh, must believe that God is, and that He is a rewarder of them that hope in Him.” (Heb. xi. 6.)”