The Lord permits trials in order that we may be cleansed from earthliness, from selfishness, from harsh, unchristlike traits of character....

O, how precious is the sweet influence of the Spirit of God as it comes to depressed or despairing souls, encouraging the faint-hearted, strengthening the feeble, and imparting courage and help to the tried servants of the Lord! O, what a God is ours, who deals gently with the erring, and manifests His patience and tenderness in adversity, and when we are overwhelmed with some great sorrow!—Patriarchs and Prophets, 657. 

The Lord permits trials in order that we may be cleansed from earthliness, from selfishness, from harsh, unchristlike traits of character. He suffers the deep waters of affliction to go over our souls, in order that we may know Him, and Jesus Christ whom He has sent, in order that we may have deep heart-longings to be cleansed from defilement, and may come forth from the trial purer, holier, happier.—Christ’s Object Lessons, 175. RRe 107

The great plan of redemption results in fully bringing back the world into God's favor. All that was lost by sin is restored. Not only man but the earth is redeemed, to be the eternal abode of the obedient. For six thousand years Satan has struggled to maintain possession of the earth. Now God's original purpose in its creation is accomplished. “The saints of the Most High shall take the kingdom, and possess the kingdom forever, even forever and ever.” Daniel 7:18. Hvn 78

I will be glad and rejoice in Thy mercy: for Thou hast considered my trouble; Thou hast known my soul in adversities. Psalm 31:7. KJV