The direct implication of the question is that God is the one who tempted Adam and Eve. If God tempted man, the reason for the fall of man is not man nor the serpent but God. Therefore, God is guilty of the sin of man. Notice that this is an attempt to transfer the guilt of sin from man, the doer of the sin, to God. This is the very line of thought followed by Adam and Eve after their fall. Notice Adam’s own words, “The woman WHOM THOU GAVEST to be with me, she gave me of the tree, and I did eat.” (Genesis 3:12)
Did God tempt Adam and Eve? The Bible tells us that God does not tempt any man.
“Let no man say when he is tempted, I am tempted of God: for God cannot be tempted with evil, neither tempteth he any man.” (James 1:13)
The Devil is responsible for tempting Adam and Eve, not God. However, this does not deny the reality that Adam and Eve are still guilty of their sins. “Every man is tempted, when he is drawn away of his own lust, and enticed. Then when lust hath conceived, it bringeth forth sin: and sin, when it is finished, bringeth forth death.” (James 1:14, 15) Adam and Eve were tempted not because of the temptation but because they chose to be tempted.
Now back to the question, why did God allow the serpent to go near Eve and Adam? God did not allow this event to happen to cause Adam and Eve to sin. If so, is there any alternative? Sure!
On the other side of the coin, the presence of the serpent, and even of the tree of the knowledge of good and evil, in the garden provides Adam and Eve the opportunity to exercise their faith in God. “And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat: But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.” (Genesis 2:16, 17) If Adam and Eve had genuine faith in the words of God, If the couple believes that what God is saying is true, they would not disobey. “Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works.” (James 2:18)
Allowing the serpent to cling on the forbidden tree, God also provided Adam and Eve the opportunity to demonstrate their love for God in front of the devil. “For this demonstrates our love for God: We keep his commandments, and his commandments are not difficult.” (1 John 5:3 ISV) And Oh how sweet is the implication, God had absolute faith in humanity!
If the garden of Eden was a setup, it was not a setup for the fall of man, it was a setup to put the devil to shame. If we did not choose to fall, Oh how glorious it would have been! But instead of bringing shame to Satan, we brought shame to God. Forgive us, Lord!
Is there hope for humanity? “And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.” (Genesis 3:15) What Adam failed to do in the garden, Jesus accomplished at Calvary. Praise the Lord!