Wherever this living faith exists, it must have the hope of eternal life as its inseparable companion, or rather must of itself beget and manifest it; where it is wanting, however clearly and elegantly we may discourse of faith, it is certain we have it not. For if faith is (as has been said) a firm persuasion of the truth of God – a persuasion that it can never be false, never deceive, never be in vain, those who have received this assurance must at the same time expect that God will perform his promises, which in their conviction are absolutely true; so that in one word hope is nothing more than the expectation of those things which faith previously believes to have been truly promised by God.

Thus, faith believes that God is true; hope expects that in due season he will manifest his truth. Faith believes that he is our Father; hope expects that he will always act the part of a Father towards us. Faith believes that eternal life has been given to us; hope expects that it will one day be revealed. Faith is the foundation on which hope rests; hope nourishes and sustains faith. For as no man can expect any thing from God without previously believing his promises, so, on the other hand, the weakness of our faith, which might grow weary and fall away, must be supported and cherished by patient hope and expectation.

For this reason Paul justly says, “We are saved by hope,” (Rom. 8: 24.) For while hope silently waits for the Lord, it restrains faith from hastening on with too much precipitation, confirms it when it might waver in regard to the promises of God or begin to doubt of their truth, refreshes it when it might be fatigued, extends its view to the final goal, so as not to allow it to give up in the middle of the course, or at the very outset. In short, by constantly renovating and reviving, it is ever and anon furnishing more vigor for perseverance.

On the whole, how necessary the reinforcements of hope are to establish faith will better appear if we reflect on the numerous forms of temptation by which those who have embraced the word of God are assailed and shaken. First, the Lord often keeps us in suspense, by delaying the fulfillment of his promises much longer than we could wish. Here the office of hope is to perform what the prophet enjoins, “Though it tarry, wait for it,” (Hab. 2: 3.) Sometimes he not only permits faith to grow languid, but even openly manifests his displeasure.

Here there is still greater necessity for the aid of hope, that we may be able to say with another prophet, “I will wait upon the Lord that hideth his face from the house of Jacob, and I will look for him,” (Isaiah 8: 17.) Scoffers also rise up, as Peter tells us, and asks where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation,” (2 Pet. 3: 4.) Nay, the world and the flesh insinuate the same thing. Here faith must be supported by the patience of hope, and fixed on the contemplation of eternity, consider that “one day is with the Lord as a thousand years, and a thousand years as one day,” (2 Pet. 3: 8; Ps. 90: 4.)

John Calvin, Institutes of the Christian Religion, 3.2.42