One must understand that God the Father is an all knowing being. He knows the future before it occurs. He knew that by placing Satan and his followers on earth that they would tempt Eve and she would succomb to their temptation. God the Father even called and chose a Savior of the world before ever placing Adam and Eve in the garden of Eden knowing full well what the outcome would be. Certainly with God's foreknowledge he could have changed the whole plan before it happened and avoided it altogether. But He didn't. Why?
The answer is because this was the plan all along that mankind enter a fallen mortal world and experience good and evil. God himself even said that once Adam and Eve had partaken of the forbidden fruit that they had become like the Gods.
Genesis 3:22
22 And the Lord God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever:
God, being a good being, wanted his creatures to become more like himself. This is one of the reason He set up the entire scenario was to allow mankind to enter a fallen state and experience good and evil. He also provided a Savior before all of this took place so that every fallen man who enters the world and receives a body would eventually be resurrected to an immortal body and live forever. Thus the end game was give mankind a knowledge of good and evil and become more like God all the while ensuring that they would all eventually resurrect and become immortal and live forever.
This life is a learning ground for us to choose good over evil and become the best beings we can, given the circumstances. Free will is critical for us to progress. Through free choice we make decisions in and of ourselves what kind of being we wish to become. Those who choose to be a good being of their own free will are truly good beings. Who would you trust more, a being who is forced to be a good being or a being who had chosen to be a good being of his own free will and choice?