Of the many devices of which God's patient and condescending grace made use to stir up and strengthen faith, one of the chief was - the Covenant. In more than one way God sought to effect this by His Covenant. First of all, His Covenant was always a revelation of His purposes, holding out, in definite promise, what God was willing to work in those with whom the Covenant was made. It was a Divine pattern of the work God intended to do in their behalf, that they might know what to desire and expect, that their faith might nourish itself with the very things, though as yet unseen, which God was working out. Then, the Covenant was meant to be a security and guarantee, as simple and plain and humanlike as the Divine glory could make it, that the very things which God had promised would indeed be brought to pass and wrought out in those with whom He had entered into covenant. Amid all delay and disappointment, and apparent failure of the Divine promises, the Covenant was to be the anchor of the soul, pledging the Divine veracity and faithfulness and unchangeableness for the certain performance of what had been promised. And so the Covenant was, above all, to give man a hold upon God, as the Covenant-keeping God, to link him to God Himself in expectation and hope, to bring him to make God Himself alone the portion and the strength of his soul.
Oh that we knew how God longs that we should trust Him, and how surely His every promise must be fulfilled to those who do so! Oh that we knew how it is owing to nothing but our unbelief that we cannot enter into the possession of God's promises, and that God cannot -yes, cannot---do His mighty works in us, and for us, and through us! Oh that we knew how one of the surest remedies for our unbelief---the divinely chosen cure for it---is the Covenant into which God has entered with us! The whole dispensation of the Spirit, the whole economy of grace in Christ Jesus, the whole of our spiritual life, the whole of the health and growth and strength of the Church, has been laid down and provided for, and secured in the New Covenant. No wonder that, where that Covenant, with its wonderful promises, is so little thought of, its plea for an abounding and unhesitating confidence in God so little understood, its claim upon the faithfulness of the Omnipotent God so little tested; no wonder that Christian life should miss the joy and the strength, the holiness and the heavenliness which God meant and so clearly promised that it should have.
Let us listen to the words in which God's Word calls us to know, and worship, and trust our Covenant-keeping God it may be we shall find what we have been looking for: the deeper, the full experience of all God's grace can do in us. In our text Moses says: "Know therefore that the Lord thy God, He is God, the faithful God, which keepeth covenant with them that love Him." Hear what God says in Isaiah: "The mountains shall depart, and the hills be removed; but My kindness shall not depart from thee, neither shall My covenant of peace be removed, saith the Lord that hath mercy on thee." More sure than any mountain is the fulfillment of every Covenant promise. Of the New Covenant, in Jeremiah, God speaks: "I will make an everlasting covenant with them, that I will not turn away from them, to do them good; but I will put My fear in their hearts, that they shall not depart from Me." The Covenant secures alike that God will not turn from us, nor we depart from Him: He undertakes both for Himself and us.
Let us ask very earnestly whether the lack in our Christian life, and specially in our faith, is not owing to the neglect of the Covenant. We have not worshipped nor trusted the Covenant-keeping God. Our soul has not done what God called us to---"to take hold of His Covenant," " to remember the Covenant"; is it wonder that our faith has failed and come short of the blessing? God could not fulfil His promises in us. If we will begin to examine into the terms of the Covenant, as the title-deeds of our inheritance, and the riches we are to possess even here on earth; if we will think of the certainty of their fulfillment, more sure than the foundations of the everlasting mountains; if we will turn to the God who has engaged to do all for us, who keepeth covenant for ever, our life will become different from what it has been; it can, and will be, all that God would make it.
From The Two Covenants by Andrew Murray