The following us a powerful explanation of God's covenant of grace enacted through Noah and depicted through the rainbow. It comes from a portion of the writing of Theologian A.W. Pink in his book on The Divine Covenants, (http://www.pbministries.org/books/pink/Divine_Covenants/divine_covenants_03.htm), which I commend to you in full. It's powerful stuff!!!
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FROM A.W. PINK::
But God’s bow in the clouds was not only an assurance unto men at large that no more would the world be destroyed by a flood, it was also the seal of confirmation of the covenant which God had made with the elect seed, the children of faith. Blessed it is to know that, not only our eyes, but His too are upon the bow; and thus this gives us fellowship with Himself in that which tells of the storm being over, of peace displacing turmoil, of the dark gloom now being irradiated by the shining of the sun. It was the rain which broke up the light into its separate rays, now reflected in the bow: the blue or heavenly ray, the yellow or golden ray, the crimson ray of atonement. Thus it is in the everlasting covenant that God is fully revealed as light and as love, as righteous yet merciful, merciful yet righteous. The covenant of grace is beautifully expressed in the rainbow. For the following nine points on this covenant we are indebted to a sermon by Ebenezer Erskine, preached about 1730.
1. It is of God’s ordering: "I have set my bow in the clouds." So the covenant of grace is of God’s ordering: "I have made a covenant with my chosen" (Ps. 89). Though it be our duty to "take hold of" the covenant (Isa. 56:4), and to come under engagements through the grace thereof, yet we have no part in appointing or ordering it. The covenant of grace could no more have been made by man, than he can form a bow in the clouds.
2. The bow was set in the clouds upon God’s smelling a sweet savor in Noah’s sacrifice; so that the covenant of grace is founded upon and sealed with the blood of the Lamb—a reminder thereof being set before us every time we sit down to partake of the Lord’s Supper.
3. The rainbow is a divine security that the waters should return no more to destroy the earth; so the covenant of grace guarantees against the deluge of God’s wrath, that it shall never return again to destroy any soul that by faith flees to Christ (Isa. 54:9).
4. It is the sun which gives being to the rainbow. Remove it from the firmament and there could not be its glorious reflection in the clouds. So Christ, the Sun of righteousness, gives being to the covenant of grace. He is its very life and substance: "I will preserve thee and give thee for a covenant of the people" (Isa. 49:8).
5. Although the arch of the bow is high above us, reaching to the heaven, yet the ends of it stoop down and reach to the earth. Just so it is with the covenant of grace: although the great covenant Head be in heaven, yet, through the gospel, He stoops down to men upon earth "The word is nigh thee" (Rom. 10:6-8).
6. God’s bow in the clouds is very extensive, reaching from one end of heaven to the other; so His covenant of grace is wide in its reach, stretching back to eternity past and reaching forward to eternity future, embracing some out of every nation and kindred, and tribe and tongue.
7. As the rainbow is a security against a universal deluge, so it is also a prognostic of refreshing showers of rain to the thirsty earth. So the bow of the covenant which encircles the throne of God (Rev. 4:3) not only secures against vindictive wrath, but gives assurance of the rain—the Spirit’s influences.
8. The visible appearance of the rainbow is but of a short continuance, for usually it appears only for a few minutes and then vanishes. So the sensible and lively views which the believer gets of the covenant of grace are usually of brief duration.
9. Although the rainbow disappears, and that for a long while together, yet we do not conclude therefrom that God’s covenant is broken or that a flood will come and destroy the earth. So too the saint may not now be favored with a sensible sight of the covenant of grace; yet the remembrance of former views thereof will keep the soul from fears of wrath.
The following paragraph is quoted from our work Gleanings in Genesis. "There are many parallels between the rainbow and God’s grace. As the rainbow is the joint-product of storm and sunshine, so grace is the unmerited favor of God appearing on the dark background of the creature’s sin. As the rainbow is the effect of the sun shining on the drops of rain in a cloud, so Divine grace is manifested by God’s love shining through the blood shed by our blessed Redeemer. As the rainbow is the telling out of the varied hues of the white light, so the ‘manifold grace of God’ (1 Pet. 4:10) is the ultimate expression of God’s heart. As nature knows nothing more exquisitely beautiful than the rainbow, so heaven itself knows nothing that surpasses in loveliness the wondrous grace of God. As the rainbow is the union of heaven and earth-spanning the sky and reaching down to the ground—so grace in the one Mediator has brought together God and man. As the rainbow is a public sign of God hung out in the heavens that all may see it, so ‘the grace of God that bringeth salvation hath appeared to all men’ (Titus 2:11). Finally, as the rainbow has been displayed throughout all the past forty centuries, so in the ages to come God will show forth ‘the exceeding riches of His grace in His kindness toward us through Christ Jesus’ (Eph. 2:7)."
