Q: Why did God let Adam and Eve fail if he really wanted a perfect world?
A: From The Urantia Book:
There has been no “fall of man.” The history of the human race is one of progressive evolution and the Adamic bestowal left the world peoples greatly improved over their previous biologic condition. (75:8.1)
When once you grasp the idea of God as a true and loving Father, the only concept which Jesus ever taught, you must forthwith, in all consistency, utterly abandon all those primitive notions about God as an offended monarch, a stern and all-powerful ruler whose chief delight is to detect his subjects in wrongdoing and to see that they are adequately punished, unless some being almost equal to himself should volunteer to suffer for them, to die as a substitute and in their stead. (188:4.8)
The barbarous idea of appeasing an angry God, of propitiating an offended Lord, of winning the favor of Deity through sacrifices and penance and even by the shedding of blood, represents a religion wholly puerile and primitive, a philosophy unworthy of an enlightened age of science and truth. Such beliefs are utterly repulsive to the celestial beings and the divine rulers who serve and reign in the universes. It is an affront to God to believe, hold, or teach that innocent blood must be shed in order to win his favor or to divert the fictitious divine wrath. (4:5.4)
“But, my son, you should know that the Father does not purposely afflict his children. Man brings down upon himself unnecessary affliction as a result of his persistent refusal to walk in the better ways of the divine will. Affliction is potential in evil, but much of it has been produced by sin and iniquity. Many unusual events have transpired on this world, and it is not strange that all thinking men should be perplexed by the scenes of suffering and affliction which they witness. But of one thing you may be sure: The Father does not send affliction as an arbitrary punishment for wrongdoing. The imperfections and handicaps of evil are inherent; the penalties of sin are inevitable; the destroying consequences of iniquity are inexorable. Man should not blame God for those afflictions which are the natural result of the life which he chooses to live; neither should man complain of those experiences which are a part of life as it is lived on this world. It is the Father’s will that mortal man should work persistently and consistently toward the betterment of his estate on earth. Intelligent application would enable man to overcome much of his earthly misery.” Jesus, (148:5.3)
Then Jesus made this final statement: “The Father in heaven does not willingly afflict the children of men. Man suffers, first, from the accidents of time and the imperfections of the evil of an immature physical existence. Next, he suffers the inexorable consequences of sin–the transgression of the laws of life and light. And finally, man reaps the harvest of his own iniquitous persistence in rebellion against the righteous rule of heaven on earth. But man’s miseries are not a personal visitation of divine judgment. Man can, and will, do much to lessen his temporal sufferings. But once and for all be delivered from the superstition that God afflicts man at the behest of the evil one. Study the Book of Job just to discover how many wrong ideas of God even good men may honestly entertain; and then note how even the painfully afflicted Job found the God of comfort and salvation in spite of such erroneous teachings. At last his faith pierced the clouds of suffering to discern the light of life pouring forth from the Father as healing mercy and everlasting righteousness.” Jesus, (148:6.11)
Please see Paper 74 Adam and Eve for the most complete story of these two beings, including their “fall.”